Help needed - Poor Running & Lack of Combustion in #3 & #4 Cylinders

[Mach VIII]

Hello all,

 

Been a lurker for the last year and I'm finally posting as I need some help and couldn't find the answers I was after in prior posts. I'm afraid my V4 thinks it's only a V-twin! Forgive me that this will be rather long, as I want to give complete information in hopes that will be better able to assist me.

 

Background: I have an '89 VR (Cali model, if it matters) that I bought almost exactly a year ago and have been slowly restoring and returning to road duty on a budget. Approximately 34,000 miles. When I bought the bike it would only run on full choke, and poorly at that. Previous owner bought it that way as a project. He attempted the shotgun cleaning method but that didn't work, then he lost interest. I have no other prior service history, though I can see that a lot of the prior "modifications" were poorly executed, so I have little faith in the competence of the PO (not who I bought it from) to properly repair and maintain the bike. Anyhow, I removed carbs and had a friend who operates an independent bike shop fully clean, rebuild, and bench synch the carbs. I have since installed and also installed new NGK iridium plugs.

 

Running and performance: Bike has been running now for a few months, but not especially well. I have taken it out on a few "shakedown" rides of around 100 miles or so in hopes that riding it around would help it heal after coming out of an unknown period of hibernation. That hasn't fixed it. At start-up it fires right up on full choke but doesn't sound as smooth as I would expect and I hear a periodic popping that I believe to be pre-ignition or some incomplete combustion(???). Riding it it's a bit of a dog at first and I will have to feather the throttle some when I come to a stop (off of choke). It doesn't fall on its face when accelerating, it just doesn't feel as strong as it should. Mileage is horrible - I'm having to get gas after only around 75 miles or so. After riding for quite some distance (more than 15 miles) and especially after really flogging it on a more sustained basis, it seems to run noticeably better, although never 100% (at least I don't think). Still some popping on deceleration and doesn't always want to idle at stops if I let off the throttle. So in my estimation it seems to be running "kinda decent" at these times, though having never ridden one of these, I don't know what a properly running one should feel like. For reference I have owned several V45 Magnas, a ZX-12R (my main bike), and other inline 4's, among others. I have ridden a VMax once, but it was a number of years ago now. My memory of it is pretty limited, but my Venture doesn't feel nearly as powerful as I remember the VMax. My ZX-12R is in another stratosphere, but that's not an apt comparison.

Current Symptoms & efforts to diagnose: I've had a suspicion that #4 is not firing, or at least not all the time. I'd previously used a pointable thermometer and saw the temperature (measured pointing at the jug) was significantly lower on #4 as compared to others. Unfortunately, I only ever checked this after starting the bike up in the driveway and riding up and down my street, rather than after an extended ride where it was running "better." I had also previously checked the spark plug in #4 and saw it was wet and likely fouled (cleaned, dried it, and reinstalled since it only had a couple hundred miles on it).

 

This past Sunday I set about to figure out what was wrong, and fix it if I could. I started it up in the driveway on full choke and it fired right up. After letting it idle for a couple minutes I pulled the plug wire off of #4 - no change whatsoever. I stuffed another plug in it while it was still running and I do have spark - I both felt it and touched the plug to the engine and saw spark. I can't really say how strong, as it was in bright daylight, but I could definitely see it. More surprising to me was that I pulled the wire on #3 and had the very same outcome. I then pulled #1 and it immediately started to stumble, so I reinstalled. Didn't bother pulling #2 as it obviously had spark since the bike didn't immediately die when I pulled #1 .

 

Pulled the plugs and inspected. #4 was wet and clearly fouled. Others were ok (not great), with the white ceramics a bit sooty, but not wet like #4 . Weirdly, #3 actually looked the best. Gapped and installed new NGK DPR8EA-9 plugs and crossed my fingers. I also checked the pilot mixture screws and discovered they were set anywhere from 3/4 out to 3 full turns out. I adjusted them all to 2 1/2 turns out as a baseline based upon what I read in other posts. Fired it up and it was no different. Could still pull the plug wires off of #3 & #4 without any effect. I probably should have taken the bike out and really run it before starting all this, but I didn't. Was thinking instead about having to work on a hot engine.

 

Next I did a compression test. 1=190; 2=195; 3=195; 4=175 (eventually). So, #4 was lower and slower to pump up. No idea if/when valve lash has ever been inspected/adjusted. I see that it requires a special tool and shims, neither of which I have. I now suspect this may be at least part of the cause of my problems, but 175 psi still seems like it should be more than enough compression to support combustion.

 

I continued on with checking ignition components, thinking the trouble may lay there. Holy hell what a job to get to the TCI and coils. I checked resistance on the pickup coil at the plug and all tested wires were within spec. I then checked primary resistance on the ignition coils and all 4 were in spec. at 2.9 ohms. I then checked secondary resistance by inserting a probe into plug cap and got the following resistance numbers: 1=22.5; 2=24; 3=22.1; 23.7. At first these numbers alarmed me as they are all much higher than the 15 ohm maximum specified in the service manual, but then I read that the plug cap should be 10 ohms itself +/- 10%, so if I subtract this out, all three coils are in spec for secondary resistance as well. I suppose I could remove the wires from the coils and try to test at the coil directly, but access is limited and I know I'm getting (at least some) spark to all 4 cylinders. Let me say I am not at all excited at the prospect of pulling the upper fairing to change out coils unless it is absolutely necessary. Considering they all test about the same, I'm thinking they're ok, but you guys are the experts on these bikes, not I. Those numbers also lead me to think the wires and ends must be (at least) ok too (I took apart plug wire and end for #4 and everything looked fine (no green corrosion), then I clipped a 1/4" off both ends of the wire and re-assembled).

 

I got the TCI out of its stock location as well. From what I've read these can be the source of all kinds of poor running conditions as they start to fail. It is weird to me that when they fail it is not a complete failure, as that has been my past experience with CDI's. I can't help but wonder if this magic black box is the source of my problems. I did open the cover, but wasn't brave enough to dig out the soldering iron and desolder the pins to the main plugs just so I could look at the top of the motherboard and the diodes that are known to fail. My understanding from reading past posts is that if the TCI is not working properly, there's no fixing it. The diode replacement and resoldering of various connections is only preventative maintenance on properly functioning units. So my thinking was to leave it alone for now, since if it's broke I can't fix it, and if it ain't broke, I might just screw it up with my extremely limited soldering skills. It would certainly be helpful to have a known good one to plug in to rule in/out the TCI as a problem, but alas I do not have one and ones on ebay aren't cheap (for what may be junk anyhow). I've read about the Ignitek computer, but I don't know what my long-terms plans are for the bike and am concerned about budget. Besides, I don't want to just go throwing parts at it - especially expensive ones.

 

I also checked to see if there's fuel getting to all 4 carbs and there is. I opened the drains on each of them and got full bowl's worth from each.

 

So I'm not really sure where to go next with it. Based upon the compression test, I am wondering if valve adjustment should be next, though candidly I was hoping to avoid this job. I welcome suggestions, comments, offers of help, commiseration, jokes at my expense as the FNG, and further questions. I've done a ton of other work on the bike and I'm really anxious to have it finally "done." If I can ever get it running properly, I can turn my attention to the non-functioning cruise control (Grrrrr) and do a final "detailing" of the bike, before planning some longer trips.

 

Thanks all for your patience in reading along, and thanks in advance for your assistance.

 

[P.S. - If I have placed this post in the wrong folder, please feel free to move it and let me know where it should've been in the first place]

[luvmy40]

Are the plug wires and caps original?

 

Fire it up in a dark environment and mist the wires with a spray bottle of water, Look for arcing.

 

I'd be willing to bet that if the coils ohm out correctly and the problem is constant, as in not only after it warms up(which can cause a coil that ohms out correctly to start missing if the insulation is compromised), then your problem is likely the ignition control module(CDI).

 

Ignitech makes a great programmable after stock module for a very reasonable price.

 

https://www.ignitech.cz/en/vyrobky

 

ignitech@ignitech.cz

[saddlebum]

A couple things to check

 

Check the connections to the ignition unit and clean them. Five years ago I almost replaced one due to a misfiring #3 cylinder. While removing it I noticed the terminals where dirty so I cleaned all the terminals in the unit and connectors. The bike has run like a dream ever since. I have since found this to be an issue on a few other bikes since.

 

Also check the plug connectors.There is a spring and carbon piece inside the connector, it can all be removed and inspected to be sure you have constant contact. some times the spring gets weak and you end up with intermittent spark.

 

Another common issue. Is the Choke. In truth there is no choke. What there is, is an enrichment valve in the Carb which is opened and closed by the choke lever. Unlike a choke which cuts back on air the enrichment valve opens to allow for more fuel. These guys can often stick open. The mount to the outside of the carb and though you can access them without a complete tear down you do have to split the carbs to remove 2 of them the other 2 you can remove without splitting the carbs. They are a plunger controlled from outside the crab by tiny swivel forks that moves the plunger in and out. See pic below. These too can seize up. Wet plugs, black smoke, stumble when the engine gets warm though it may fire up ok when cold are common symptoms of this issue.

 

Also improperly or stuck floats allowing too much gas into the carb. Similar symptoms as a stuck enrichment valve but may also be accompanied by fuel coming out of the overflow tubes at idle and pouring out on the ground

Edited July 14, 2020 by saddlebum

[BlueSky]

The original spark plug caps are around 10,000 ohms and the spark plug wires are copper core and should be close to zero ohms. If you haven't done so, unscrew the caps and look at the copper core wire. the joint is not water tight and moisture gets into the joint and the copper core corrodes and turns green. If you cut off a half inch or more wire, you can most likely get to clean copper wire.

Probably does the same at the coils? Replacement NGK spark plug caps are 5,000 ohms.

[Mach VIII]

Thanks for the responses thus far.

 

I have not tried spraying the plug wires with water to look for arcing, but I can do so. I guess I'd need to use jumper cables to the battery (since it and the tray are removed) and maybe set the airbox back in place.

 

The plug wires and end caps are stock items (no idea if stock or replaced at some point). As I say, I inspected both ends of the #4 plug wire and saw no corrosion, but nipped off a 1/4" on either end. When I unscrewed the cap/boot I found a small rod that I guess must be the resistor. It was kind of white in color and I assumed it to be ceramic or something similar. No spring came out, but perhaps it was still inside the end/boot. Would the spring be on the "wire" side of the boot or the "plug" side of the boot (behind the metal piece that actually contacts the top of the spark plug)?

 

As to the "choke" plungers, I believe those are all moving freely now - that was not the case before cleaning of the carbs. I can verify free movement easily enough though since the airbox is off.

 

Again, thanks for the responses thus far.

[Mach VIII]

Not a good night in the garage last night. [sigh]

 

I checked the choke plungers and they seem to be operating correctly, so that can be ruled out.

 

Connections to the TCI looked good, but I sprayed with contact cleaner regardless.

 

I next disassembled the plug wire caps/boots. Inside I found: threaded brass plug retainer (for lack of a better name), resistor, spring, and small brass disc. The brass disc was missing from #4 . I cleaned up the parts, but struggled to figure out what order to reassemble the parts, as they did not really come out in a clear order. If someone could confirm 1) that those are ALL the parts I should find inside (excepting of course the missing disc on #4 ), and 2) the correct order of reassembly. After some figuring and fiddling, here's what I ended up doing:

 

plug boot -> spring -> disc -> resistor -> brass plug retainer

 

Also, I took the missing disc from #3 and installed it in the cap/boot for #4 just to see if that would get #4 to fire properly. I saw a picture in another post here a few days ago with all the parts laid out and describing the order of reassembly, but after looking for more than an hour, I cannot find it again.

 

Here's the maddening thing - when I check the resistance with my meter, I get no reading whatsoever. I tried assembling the parts multiple ways, but still no resistance reading on my meter. WTH?! I tried doing the secondary resistance test again on the coil by inserting a probe into the (now assembled and attached) plug cap, but again, nothing. I do not understand how my disassembly, cleaning, and reassembly of the plug boots/caps could have done this. I will say that I did use a wire brush to clean off the resistors, but I can't see how that would matter at all. Just out of curiosity, I tried to check the plug boots for continuity with my meter, but still got nothing. But I don't know, maybe the resistor is too much for the little continuity tester in my meter to overcome????

 

Not knowing what else to do, I figured I would just plug in the TCI and temporarily hook up the battery to try and start it. Well the starter clutch is now making horrible noises at me and will only occasionally spin the motor over at all. The PO told me that he had JUST replaced the starter clutch because it made horrible noises (but again, gave up on making the bike a runner after realizing the carbs would need to come off). In my time of ownership it has occasionally done this, but mostly when the motor otherwise seems "unhappy." For example, it has done this far less since I removed, cleaned, and reinstalled the carbs. Usually if I wait a couple seconds and try again it will engage properly. Not last night. So now I can't even check to see if I have spark. From doing some reading on the subject, my guess is that the 3 bolts on the starter clutch have backed out. Oh joy.

 

It's a good thing I don't live next to a body of water, or this thing might have ended up at the bottom of it last night I was so frustrated.

[Patch]

OK, you've talked me into it!

Now I warns y'all I have some gaps - so if and in the unlikely possibility I start talkin Suzuki or I think U's is playin a yoke on me, I expect "kindness" and "understanding" "respect" for all the experience that has fallin from my shelving would be appreciated too!

Finally NO PICKING ON MY Henglish:nanner:

[Patch]

This is a post, lots of detail, takes time, but, worth the read.

 

In this post you show that you have done much of what would have needed doing anyways!

However NOT in the correct order.

 

Lets gets get started:

 

 

Hello all,

 

Been a lurker for the last year and I'm finally posting as I need some help and couldn't find the answers I was after in prior posts. I'm afraid my V4 thinks it's only a V-twin! Forgive me that this will be rather long, as I want to give complete information in hopes that will be better able to assist me.

 

Well welcome to the Club, what took you so long.

 

Background: I have an '89 VR (Cali model, if it matters) that I bought almost exactly a year ago and have been slowly restoring and returning to road duty on a budget. Approximately 34,000 miles. When I bought the bike it would only run on full choke, and poorly at that. Previous owner bought it that way as a project. He attempted the shotgun cleaning method but that didn't work, then he lost interest. I have no other prior service history, though I can see that a lot of the prior "modifications" were poorly executed, so I have little faith in the competence of the PO (not who I bought it from) to properly repair and maintain the bike. Anyhow, I removed carbs and had a friend who operates an independent bike shop fully clean, rebuild, and bench synch the carbs. I have since installed and also installed new NGK iridium plugs.

 

What kit? What jet sizing? are all jets the same size? Needle size & clipped or not?

 

Running and performance: Bike has been running now for a few months, but not especially well. I have taken it out on a few "shakedown" rides of around 100 miles or so in hopes that riding it around would help it heal after coming out of an unknown period of hibernation. That hasn't fixed it. At start-up it fires right up on full choke but doesn't sound as smooth as I would expect and I hear a periodic popping that I believe to be pre-ignition or some incomplete combustion(???). Riding it it's a bit of a dog at first and I will have to feather the throttle some when I come to a stop (off of choke). It doesn't fall on its face when accelerating, it just doesn't feel as strong as it should. Mileage is horrible - I'm having to get gas after only around 75 miles or so. After riding for quite some distance (more than 15 miles) and especially after really flogging it on a more sustained basis, it seems to run noticeably better, although never 100% (at least I don't think).So what we have here is a failure to communicate as in the setup is wrong. More on this further down.

Still some popping on deceleration and doesn't always want to idle at stops if I let off the throttle.

So in my estimation it seems to be running "kinda decent" at these times, though having never ridden one of these, I don't know what a properly running one should feel like. For reference I have owned several V45 Magnas, a ZX-12R (my main bike), and other inline 4's, among others. I have ridden a VMax once, but it was a number of years ago now. My memory of it is pretty limited, but my Venture doesn't feel nearly as powerful as I remember the VMax. My ZX-12R is in another stratosphere, but that's not an apt comparison. Well this bike is a steady strong pull when shifting correctly at the right RPM's! It is not like a straight for, nor should she be, the lower inertia while slower to gain RPM will however pull her thru when passing in wind, up hills and past the buffering of a flatnose Mac;;;;; its a touring bike made for long distance not 1/4's!

Current Symptoms & efforts to diagnose: I've had a suspicion that #4 is not firing, or at least not all the time. I'd previously used a pointable thermometer and saw the temperature (measured pointing at the jug) was significantly lower on #4 as compared to others. Unfortunately, I only ever checked this after starting the bike up in the driveway ] And can be done with a spray bottle as well but yes within the first minutes of the engine running,,, because it is a liquid cooled bike not air cooled. That means that the temps will rise thru conduction as the coolant temp rises! K

 

[and riding up and down my street, rather than after an extended ride where it was running "better." I had also previously checked the spark plug in #4 and saw it was wet and likely fouled (cleaned, dried it, and reinstalled since it only had a couple hundred miles on it). More on this later

 

This past Sunday I set about to figure out what was wrong, and fix it if I could. I started it up in the driveway on full choke and it fired right up. After letting it idle for a couple minutes I pulled the plug wire off of #4 - no change whatsoever. I stuffed another plug in it while it was still running and I do have spark - I both felt it and touched the plug to the engine and saw spark. I can't really say how strong, as it was in bright daylight, but I could definitely see it. More surprising to me was that I pulled the wire on #3 and had the very same outcome.

I then pulled #1 and it immediately started to stumble, so I reinstalled. Didn't bother pulling #2 as it obviously had spark since the bike didn't immediately die when I pulled #1 . So what does #'s 3&4 2&1 have in common? Also guys keep in mind that the 89 pickup is different than the 90+ system.

turn to page 7-33 top right hand corner, you see 4 coils, but there are actually 2, which means "wasted spark" system. There is only one sure fire way to test the system completely except for advance, which only cost $6ish and 30 minutes of our time, page 7-35 today we refer to it as a "gap tester" available everywhere!

 

 

Ok answer our questions above, yes the carbs need removing one way or another.

I will continue to add to your posting a bit later in the day, but pleas, answer the questions first.

See ya in a bit

[Patch]

Would you like me to keep breaking it down for you?

If you feel it is too overwhelming I would suggest you develop an action plan first, then repair and test each repair before moving on.

[Mach VIII]

Thank you for the replies.

 

You asked about what "jet kit" was used. It was just the K&L rebuild kits, so not a "jet kit" as such. I expect the jetting and needles to be stock, though I didn't do it myself, so I can't say with certainty. To my recollection, the needles are not of the adjustable type (with a circlip that can be moved to different positions). As I say, they were professionally taken down, thoroughly cleaned, and reassembled.

 

You posed the question about what cylinders 3&4 have in common, but I don't know, aside from both being on the same side of the engine. I also do not understand what you mean when you say that there are really only 2 coils. My understanding is that there are 4 coils - one for each cylinder and that "downstream" of the TCI, they operate entirely independent of one another. If my understanding is wrong, please let me know. But as I said, I really do not understand just what your asking me, so I do not know how to answer. I did however order a spark gap tester from Motion Pro so that I can check the relative strength of the spark in each cylinder.

 

As I mentioned in my most recent post, the starter clutch has completely failed, so I am at a bit of a standstill in terms of diagnosing the combustion/running issues, seeing as I cannot even turn the motor over at present. I got it apart over the weekend, including removal of the flywheel and starter clutch. As expected, the bolts were loose (and threads damaged). Although not cracked, the SC was damaged and two of the springs were broken with parts of them missing (GULP!). The surface on the 72 tooth gear was slightly washboard-like as well. So, new SC parts have been ordered and I await their arrival so I can get back to the original task at hand.

[Mach VIII]

Oh yeah, and can anyone tell me the correct order of reassembly for the spark plug boots/caps? As mentioned above, I took them apart to inspect and clean, but because of the way they came apart, I don't know the the correct order of the parts. I've tried multiple configurations but can't seem to get it right, as I no longer get any resistance or even continuity readings in them. I would at least like to get this issue sorted out while I await my starter clutch parts.

 

Thanks!

[Patch]

Mach, in a forum or club like ours we try to share knowledge sometimes its very specific other times it takes the form of a more general understanding in theory!

Analyzing a complaint over the net then coming up with a plan can take time. Yours was very specific containing all the clues I needed to understand the main issues!

As I mentioned you had already gone thru much of what we needed to know in your first post. The problems you found or created afterwords are incidental from my point of view.

I also mentioned that your procedures were out of order and is why you find yourself where you are at the moment.

You said the carb was rebuilt; now you say it was cleaned changing only minor parts!

The reason I asked about the jets is very clear to me and others.

The pairing is a general notation and is a valid one. Within the forum many know where I was going with it and, some rookie somewhere sometime down the road will read it and learn from the queue.

As you mentioned you have been a lurker for a long time then you also know I am not a halfway kind of fella, all in or all out.

Your answers are a combination of the first half and the second half. The first clue was the pilots.

Assumptions are they say The Mother to many of our problems, not answers

Best of luck to you

 

 

Thank you for the replies.

 

You asked about what "jet kit" was used. It was just the K&L rebuild kits, so not a "jet kit" as such. I expect the jetting and needles to be stock, though I didn't do it myself, so I can't say with certainty. To my recollection, the needles are not of the adjustable type (with a circlip that can be moved to different positions). As I say, they were professionally taken down, thoroughly cleaned, and reassembled.

 

You posed the question about what cylinders 3&4 have in common, but I don't know, aside from both being on the same side of the engine. I also do not understand what you mean when you say that there are really only 2 coils. My understanding is that there are 4 coils - one for each cylinder and that "downstream" of the TCI, they operate entirely independent of one another. If my understanding is wrong, please let me know. But as I said, I really do not understand just what your asking me, so I do not know how to answer. I did however order a spark gap tester from Motion Pro so that I can check the relative strength of the spark in each cylinder.

 

As I mentioned in my most recent post, the starter clutch has completely failed, so I am at a bit of a standstill in terms of diagnosing the combustion/running issues, seeing as I cannot even turn the motor over at present. I got it apart over the weekend, including removal of the flywheel and starter clutch. As expected, the bolts were loose (and threads damaged). Although not cracked, the SC was damaged and two of the springs were broken with parts of them missing (GULP!). The surface on the 72 tooth gear was slightly washboard-like as well. So, new SC parts have been ordered and I await their arrival so I can get back to the original task at hand.

[luvmy40]

Oh yeah, and can anyone tell me the correct order of reassembly for the spark plug boots/caps? As mentioned above, I took them apart to inspect and clean, but because of the way they came apart, I don't know the the correct order of the parts. I've tried multiple configurations but can't seem to get it right, as I no longer get any resistance or even continuity readings in them. I would at least like to get this issue sorted out while I await my starter clutch parts.

 

Thanks!

 

Here is the correct assembly

 

[Mach VIII]

Mach, in a forum or club like ours we try to share knowledge sometimes its very specific other times it takes the form of a more general understanding in theory!

Analyzing a complaint over the net then coming up with a plan can take time. Yours was very specific containing all the clues I needed to understand the main issues!

As I mentioned you had already gone thru much of what we needed to know in your first post. The problems you found or created afterwords are incidental from my point of view.

I also mentioned that your procedures were out of order and is why you find yourself where you are at the moment.

You said the carb was rebuilt; now you say it was cleaned changing only minor parts!

The reason I asked about the jets is very clear to me and others.

The pairing is a general notation and is a valid one. Within the forum many know where I was going with it and, some rookie somewhere sometime down the road will read it and learn from the queue.

As you mentioned you have been a lurker for a long time then you also know I am not a halfway kind of fella, all in or all out.

Your answers are a combination of the first half and the second half. The first clue was the pilots.

Assumptions are they say The Mother to many of our problems, not answers

Best of luck to you

 

It seems perhaps I may have offended you. That surely was not my intent, but apologies if I have done so.

 

As to carb cleaning vs. rebuilt, I don't want to get hung up on (or create confusion!) over semantics. I guess in my experience a thorough cleaning with installation of a carb rebuild kit is what is commonly meant by "rebuilding" the carbs. If my choice of term is inaccurate or led to an inaccurate picture, again, my apologies. You mention that the reason for your questions about jetting is very clear to you and others, but it is not to me, so please elaborate if you would.

 

Likewise with the "pairing" (I believe this is in reference to the spark in cylinders #3 & #4 ) - I do not understand what you are saying about how they work together. I'm not trying to argue with you - I have come here seeking knowledge from you and others with greater experience with these machines. I merely stated how I understand the coils to work, so that you and others can either confirm or help correct that understanding. Certainly I appreciate the value of having a more thorough explanation here - both for my immediate benefit, as well as for posterity and future readers.

 

"Your answers are a combination of the first half and the second half. The first clue was the pilots." Again, I am sorry, but can you explain what you mean by this?

 

Thank you again for taking the time to respond.

Edited July 20, 2020 by Mach VIII

[Mach VIII]

Here is the correct assembly

 

https://www.venturerider.org/forum/attachment.php?attachmentid=119256

 

 

Perfect. Thank you for posting this. I believe I've got the order correct then.

 

I did just come across an older post from 2010 stating that nothing abrasive should be used to clean the resistor or else it would remove a special coating. Ooooooops. If only I'd found that post about a week ago. I fear I may have just killed these caps (or the resistors anyhow). Looks like I'll be ordering some replacement NGK's as others here have recommended.

[luvmy40]

I used these on my '83 and they worked perfectly.

 

https://www.ebay.com/itm/311235893434

 

Oops! It looks like those aren't available from that seller any more. Still a google search for '76- '87 Honda GL1100 caps should do the trick.

Edited July 21, 2020 by luvmy40

[Mach VIII]

Thank you Luvmy40! Found some on ebay and placed my order.

[Patch]

Hello all,

 

Been a lurker for the last year and I'm finally posting as I need some help and couldn't find the answers I was after in prior posts. I'm afraid my V4 thinks it's only a V-twin! Forgive me that this will be rather long, as I want to give complete information in hopes that will be better able to assist me.

 

Background: I have an '89 VR (Cali model, if it matters) that I bought almost exactly a year ago and have been slowly restoring and returning to road duty on a budget. Approximately 34,000 miles. When I bought the bike it would only run on full choke, and poorly at that. Previous owner bought it that way as a project. He attempted the shotgun cleaning method but that didn't work, then he lost interest. I have no other prior service history, though I can see that a lot of the prior "modifications" were poorly executed, so I have little faith in the competence of the PO (not who I bought it from) to properly repair and maintain the bike. Anyhow, I removed carbs and had a friend who operates an independent bike shop fully clean, rebuild, and bench synch the carbs. I have since installed and also installed new NGK iridium plugs.

 

Running and performance: Bike has been running now for a few months, but not especially well. I have taken it out on a few "shakedown" rides of around 100 miles or so in hopes that riding it around would help it heal after coming out of an unknown period of hibernation. That hasn't fixed it. At start-up it fires right up on full choke but doesn't sound as smooth as I would expect and I hear a periodic popping that [I believe to be pre-ignition or some incomplete combustion(???).] Riding it it's a bit of a dog at first and I will have to feather the throttle some when I come to a stop (off of choke). It doesn't fall on its face when accelerating, it just doesn't feel as strong as it should. Mileage is horrible - I'm having to get gas after only around 75 miles or so. After riding for quite some distance (more than 15 miles) and especially after really flogging it on a more sustained basis, it seems to run noticeably better, although never 100% (at least I don't think). Still some popping on deceleration and doesn't always want to idle at stops if I let off the throttle. So in my estimation it seems to be running "kinda decent" at these times, though having never ridden one of these, I don't know what a properly running one should feel like. For reference I have owned several V45 Magnas, a ZX-12R (my main bike), and other inline 4's, among others. I have ridden a VMax once, but it was a number of years ago now. My memory of it is pretty limited, but my Venture doesn't feel nearly as powerful as I remember the VMax. My ZX-12R is in another stratosphere, but that's not an apt comparison.

Current Symptoms & efforts to diagnose: I've had a suspicion that #4 is not firing, or at least not all the time. I'd previously used a pointable thermometer and saw the temperature (measured pointing at the jug) was significantly lower on #4 as compared to others. Unfortunately, I only ever checked this after starting the bike up in the driveway and riding up and down my street, rather than after an extended ride where it was running "better." I had also previously checked the spark plug in #4 and saw it was wet and likely fouled (cleaned, dried it, and reinstalled since it only had a couple hundred miles on it).

 

This past Sunday I set about to figure out what was wrong, and fix it if I could. I started it up in the driveway on full choke and it fired right up. After letting it idle for a couple minutes I pulled the plug wire off of #4 - no change whatsoever. I stuffed another plug in it while it was still running and I do have spark - I both felt it and touched the plug to the engine and saw spark. I can't really say how strong, as it was in bright daylight, but I could definitely see it. More surprising to me was that I pulled the wire on #3 and had the very same outcome. I then pulled #1 and it immediately started to stumble, so I reinstalled. Didn't bother pulling #2 as it obviously had spark since the bike didn't immediately die when I pulled #1 .

 

Pulled the plugs and inspected. #4 was wet and clearly fouled. Others were ok (not great), with the white ceramics a bit sooty, but not wet like #4 . Weirdly, #3 actually looked the best. Gapped and installed new NGK DPR8EA-9 plugs and crossed my fingers. I also checked the pilot mixture screws and discovered they were set anywhere from 3/4 out to 3 full turns out. I adjusted them all to 2 1/2 turns out as a baseline based upon what I read in other posts. Fired it up and it was no different. Could still pull the plug wires off of #3 & #4 without any effect. I probably should have taken the bike out and really run it before starting all this, but I didn't. Was thinking instead about having to work on a hot engine.

 

Next I did a compression test.

1=190; reached limit [I believe to be pre-ignition or some incomplete combustion(???).]

2=195; "

3=195; "

4=175 (eventually). So, #4 was lower and slower to pump up.

 

If # 4 pumped to 175 between 5 & 8 cycles then this is the only correct reading on the bike.

 

No idea if/when valve lash has ever been inspected/adjusted. I see that it requires a special tool and shims, neither of which I have. I now suspect this may be at least part of the cause of my problems, but 175 psi still seems like it should be more than enough compression to support combustion.

 

I continued on with checking ignition components, thinking the trouble may lay there. Holy hell what a job to get to the TCI and coils. I checked resistance on the pickup coil at the plug and all tested wires were within spec. I then checked primary resistance on the ignition coils and all 4 were in spec. at 2.9 ohms. I then checked secondary resistance by inserting a probe into plug cap and got the following resistance numbers: 1=22.5; 2=24; 3=22.1; 23.7. At first these numbers alarmed me as they are all much higher than the 15 ohm maximum specified in the service manual, but then I read that the plug cap should be 10 ohms itself +/- 10%, so if I subtract this out, all three coils are in spec for secondary resistance as well. I suppose I could remove the wires from the coils and try to test at the coil directly, but access is limited and I know I'm getting (at least some) spark to all 4 cylinders. Let me say I am not at all excited at the prospect of pulling the upper fairing to change out coils unless it is absolutely necessary. Considering they all test about the same, I'm thinking they're ok, but you guys are the experts on these bikes, not I. Those numbers also lead me to think the wires and ends must be (at least) ok too (I took apart plug wire and end for #4 and everything looked fine (no green corrosion), then I clipped a 1/4" off both ends of the wire and re-assembled).

 

I got the TCI out of its stock location as well. From what I've read these can be the source of all kinds of poor running conditions as they start to fail. It is weird to me that when they fail it is not a complete failure, as that has been my past experience with CDI's. I can't help but wonder if this magic black box is the source of my problems. I did open the cover, but wasn't brave enough to dig out the soldering iron and desolder the pins to the main plugs just so I could look at the top of the motherboard and the diodes that are known to fail. My understanding from reading past posts is that if the TCI is not working properly, there's no fixing it. The diode replacement and resoldering of various connections is only preventative maintenance on properly functioning units. So my thinking was to leave it alone for now, since if it's broke I can't fix it, and if it ain't broke, I might just screw it up with my extremely limited soldering skills. It would certainly be helpful to have a known good one to plug in to rule in/out the TCI as a problem, but alas I do not have one and ones on ebay aren't cheap (for what may be junk anyhow). I've read about the Ignitek computer, but I don't know what my long-terms plans are for the bike and am concerned about budget. Besides, I don't want to just go throwing parts at it - especially expensive ones.

 

I also checked to see if there's fuel getting to all 4 carbs and there is. I opened the drains on each of them and got full bowl's worth from each.

 

So I'm not really sure where to go next with it. Based upon the compression test, I am wondering if valve adjustment should be next, though candidly I was hoping to avoid this job. I welcome suggestions, comments, offers of help, commiseration, jokes at my expense as the FNG, and further questions. I've done a ton of other work on the bike and I'm really anxious to have it finally "done." If I can ever get it running properly, I can turn my attention to the non-functioning cruise control (Grrrrr) and do a final "detailing" of the bike, before planning some longer trips.

 

Thanks all for your patience in reading along, and thanks in advance for your assistance.

 

[P.S. - If I have placed this post in the wrong folder, please feel free to move it and let me know where it should've been in the first place]

 

As for #3&4 ignition system

I wouldn't spend money till you get the carbon buildup down!

[Mach VIII]

As for #3&4 ignition system

I wouldn't spend money till you get the carbon buildup down!

 

 

Any specific recommendations for how best to do so once I get it running again (with a new starter clutch and new plug wire caps)? Seafoam/Techron in the crankcase or gastank? Automatic transmission fluid in the tops of the cylinders? Water slowly fed down the throats of the carbs? Kerosene in the throats of the carbs? DeepCreep sprayed into the throats of the carbs? Other ideas?

 

I've read, heard, or used the above treatments with cars over the years, but wet clutch makes me concerned they may not be appropriate for use on a bike. I've used Techron (and to a lesser extent Seafoam) as a fuel treatment for years with good results. I once used ATF in the spark plug holes to get the rings on a long-parked bike to seat and stopped it from smoking. Boy did that bike smoke like a mosquito fogger for a couple of miles though until the ATF burnt off. LOL. I wonder though if the detergent effect of ATF might help clean carbon deposits in the combustion chambers as well.

[Patch]

My opinion regarding both yours and JB recent first post were excellent post from a troubleshooting perspective!

The problem for Carl is more like Puc and I, we really provide Carl with the best of his migraines. But that is only cause we care so much about him! If we didn't do for him as much as we try too, then he would spend much more of his time playing in traffic, give a while you'll see

 

So ATF was never a good idea tho at first and many decades ago it was common place to use it for stuck piston and rings. What we found out is that the ATF would flash at combustion temperatures cause a varnish to the honing.

If carbon removing was easy to do the Direct Injection in gasoline engines would have been a better form the port injection systems and would lest much longer than 20k miles.

I have read and seen including on my own stuff that there really isn't mush passive chems that work all that well, and I'll leave it at that. In the past with the link below I have achieved as much as 22 lbs per sq reductions after treatments just as described in the post but, it takes soaking time. The creep I you will also soak the valves after spraying it thru intake and exhaust ports, then the running cycles do the rest... The final results aren't know for a couple miles tho..

 

https://www.venturerider.org/forum/showthread.php?137296-A-Case-for-Fogging&highlight=case+fogging

 

https://www.venturerider.org/forum/showthread.php?141445-87-VR-carb-problem&highlight=case+fogging

[Mach VIII]

Ok, after a brief delay, I'm back. Since my last post on the topic, I have done the following:

 

1. Replaced starter clutch (hopefully fixed for good now)

2. Replaced plug wire boots new NGK units

 

Bike now starts and runs once again, so I was able to continue troubleshooting efforts.

 

I let the bike fully warm up this time. Cylinders 1,2, and 3 are all firing. Cylinder 4 still isn't (or at least not fully/properly). I verified this by pulling the plug wire off, both at idle speeds and with it revved up. Doing so made no audible difference in the running of the bike. I used a spark gap tester (ooooh, a new tool for the toolchest) and it showed a bright blue spark. I could feel it poking me as well while I fumbled with the tool. Just to be sure, I swapped the connections and the plug wires on cylinders 3 and 4 then restarted the bike. The result was the same, number 4 was not firing. I suppose this still does not rule out the TCI malfunctioning by sending spark at the wrong time, but I am unaware of whether it is even possible (or likely) for them to fail in such a way. I'm leaning away from the TCI being the cause though, in light of observations noted below.

 

Something else I observed is an (inconsistent) hanging idle. Off choke and up to operating temperature, I got the idle set to around 1000 rpms. Airbox (with filter and lid) was installed on the carbs, though I did not tighten the clamps. If I give it some throttle, most times it will hang at about 2000 rpms, then slowly drop back down to 1000 rpms. The typical interval to drop back to 1000 rpms is between 20 and 30 seconds - so quite long in my experience dealing with a "hang-idle" on Magna CV carbs I have dealt with in the past. I had not particularly observed the hang idle condition on this bike before, but suspect it was there and I just thought I had the idle setting incorrect as I fiddled with it multiple times when trying to do "shakedown rides" on the road (found it too high sometimes, then too low and wanting to stall at stops). I suspect the hanging idle may be a significant indicator here and directly related to my apparent lack of combustion in cylinder #4 . The hang-idle issue is not present all the time (which is part of why I suspect I missed it before), but it was present much more often than not when I worked on the bike last weekend. When I test rode the bike up and down my street, it was not really noticeable as an issue, but of course the bike was not just idling and was "under load." Acceleration of the bike is "linear," which is to say that I do not feel cylinder #4 suddenly kicking in as the bike revs up and accelerates. But this was just short runs up my street in 1-2 gears at speeds no more than probably 45 mph. The bike is too disassembled now to do longer test rides.

 

With the foregoing in mind, I would like to see what steps can be taken to address the hanging idle issue - particularly ones that do not require removal and disassembly of the carbs once again. If it comes to that, so be, but I'd like to exhaust other possible remedies first. I have read about the "Shotgun" method of cleaning some circuits of these carbs. It seems interesting and easy enough to do. In reading about it I see that there is an idle mixture screw beneath the slide cover that needs to be removed. Can anyone give me a baseline setting for the number of turns out from fully seated this idle mixture screw should be set to? Since this cylinder is not operating properly already, I cannot/do not trust that whatever it is set to currently is correct. I suppose if could just check the setting on one of the carbs/cylinders that does appear to be firing, if nobody is able to provide a good baseline setting. [EDIT: please disregard the italicized sentences above. This was a misunderstanding on my part.]

 

I know that diaphragms and slide operation is a common issue to look at. I inspected the operation of the slides before reinstalling the carbs and they all 4 seem to be operating smoothly and "returning" to the closed position at that same rate of speed. My inspection of the diaphragms before cleaning also revealed no tears or holes.

 

All this to say that I'm not discounting Patch's prior suggestions re: excess carbon build-up in other cylinders. I read all of those lengthy threads. I do not, however, believe that can be the cause of cylinder #4 not currently firing. Rather it sounds like the high readings in the other three cylinders indicate a build-up of carbon in those cylinders - nonetheless, they all seem to be running well. To me, this seems to be an issue to address once I get #4 to combust properly.

 

Appreciate any further input/insight/suggestions.

Edited August 4, 2020 by Mach VIII

[Marcarl]

First off,, don't let that Patch guy fool you,, I'm not near as bad as some may have you believe and my posts don't go any longer than what might be desired.

 

Now to your issue. You mentioned that you adjusted the pilot mixture screws, and then you questioned the idle mixture screws that led me to think that you really haven't found the latter yet. Then my mind goes to thinking that maybe somebody was turning on some screws that do other things, like throttle balance.

So my question here now is: Have you sync'd the carbs? and if you did, how was that accomplished? I didn't read that you did, but it could be I missed it. If you haven't, then might I suggest to do that first?

[Mach VIII]

First off,, don't let that Patch guy fool you,, I'm not near as bad as some may have you believe and my posts don't go any longer than what might be desired.

 

Now to your issue. You mentioned that you adjusted the pilot mixture screws, and then you questioned the idle mixture screws that led me to think that you really haven't found the latter yet. Then my mind goes to thinking that maybe somebody was turning on some screws that do other things, like throttle balance.

So my question here now is: Have you sync'd the carbs? and if you did, how was that accomplished? I didn't read that you did, but it could be I missed it. If you haven't, then might I suggest to do that first?

 

"Not near as bad" is good enough for me. Thanks for your reply.

 

No, I have not yet synched the carbs. My reasons are twofold: 1, I don't have a set of gauges (I've borrowed them in the past, but alas that friend has moved away), and 2, synching seemed premature considering I can't even get combustion in #4 , so any readings would be meaningless and adjustments likely counterproductive. My experience with synching carbs is that this is generally more of a "fine tuning" procedure. The carbs were "bench synched" after all, and I can't imagine them still being so far off that #4 would not even fire. But please let me know if I'm wrong.....it wouldn't be the first time (see below).

 

What I was referring to as the pilot mixture screws are the ones that are accessible on the sides of the carb bodies without need to remove the carbs from the bike or removing the slide covers. They are at the 6 O'clock position just below the slide covers. I misspoke in my last post due to a misunderstanding on my part. I misinterpreted the photos and description of the "Shotgun" cleaning method and thought what was being identified as the "idle mixture screw" was something hidden under the slide cover (requiring its removal to access) and different from what I previously adjusted (to 2 1/2 turns out from seated). https://vmax.lvlhead.com/tips/shotgun.htm After looking at the photos again, I see that is not the case. What I separately referred to earlier as the "pilot mixture screw" and then as the "idle mixture screw" in my last post are one in the same. Sorry for the confusion I created with my last post. I was not mistakenly turning the adjuster screws used sych the carbs (thus throwing them way out of synch).

 

Here's a picture I just saw in another thread showing the location of the screws I adjusted to 2 1/2 out from fully seated. My anti-tamper plugs are obviously already removed on my carbs.

 

Thanks again for all the help on this. I'm just itching to get this bike finished up and to ride it. But 3 cylinders just isn't cutting it - especially when I need to refuel at around 75 miles.

Edited August 4, 2020 by Mach VIII

[luvmy40]

So, stupid question; If #4 isn't firing, is the spark plug fuel fouled or dry? If you really have a hot blue spark that jumps 1/4"(I think that was this thread) on the # 4 jug, I'd bet the plug is dry, indicating no fuel being aspirated.

 

BTW, these engines will run like a scalded dog on 3 cylinders it's even tough to hear the the miss at idle until you really get used to hearing one run right.

[Marcarl]

Interesting enough I presently have an 86 sitting in my garage because it wouldn't run without choke and wouldn't idle. It now idles and not so bad really, but #4 is not helping out one little bit. It has spark and when fed from the bottle (spray cleaner) there is no reaction, so I have determined it's not fuel. So if it has spark (should have, spark outside is good) and doesn't react to fuel spray there is only ne thing missing,,,, yah the cylinder I know,,, but it has to be compression. So I checked compression and came up with an amazing 60lbs. So I did a 'leak-down' test and found that the exhaust valves were constantly letting out air when the cylinder was pressurized from an air hose. So far the prognosis is that the exhaust valves aren't closing, at least not well enough to make a good seal. The clearance at the cam is a measly .006", not near enough for spec, but enough to allow and tell me the valves should be fully closed. Not onto the next step just yet.

Sounds like we may have similar issues,,,,, interesting?!?!