Mach VIII

I looked it up on Partzilla and indeed it does appear to be the same part number. Thank you very much for your kind offer. Before looking it up, I didn't realize it was a commonly used part and still available from Yamaha. If it's convenient and easy for you to get, then I'll be happy to take you up on your offer. But I really would not want you to go to any great trouble to get it (you mentioned your motor is in "storage"). I think the part is only around $8, plus shipping.

Well this is a bit embarrassing. I'm looking for a timing inspection window plug.....perhaps there is a better/more correct name. It is the small round threaded plug on the stator cover that is removed so you can see the timing marks. This is for a 1st Gen., Mk.II. Mine would NOT break loose without a big fight when I was checking the gaps on the valves the other day. I originally tried using a large flat-blade screwdriver, but it just cammed out the slot. I thought perhaps there was some special tool/edge in the factory tool kit for this job, but alas, I found nothing in my kit that fit. I tried other items that fit the slot better, but it just wouldn't budge and kept opening up the slot even more. Since it was already a mess, I then busted out the Dremel to cut a "new" slot in it, but that didn't work either. Eventually, I got it out using a punch and a hammer to get it to finally come loose. Not pretty. I could probably screw it back in, but I'm sure I'd have a time getting it out in the future. Plus it looks pretty bad. Soooo.....does anyone have a nice spare one of these they'd be willing to part with? I looked on Ebay but didn't see any sold separately, just entire stator covers. Thanks!

Thank you very much Freebird. Most kind and generous of you. PM sent.

Hello all, Amongst the many other repairs and maintenance items I have been undertaking to get my '89 VR project roadworthy again, I am going to adjust the valves. I inspected them last night and see that I have 5 that are out of spec (tight). I have access to shims (albeit not in a kit); however, I do not have the special tool needed to depress the buckets for removal/replacement of the shims. Is there anyone that has a tool that they would be willing to loan to me, or possibly rent, or even purchase if the price is right? I realize I am a newer member here, but I have been a long-time moderator and active member on the Honda SuperMagna Owner's Group forum, for whatever that may be worth. This bike was meant to be a low-budget project, so spending $50-$60 on a tool that I may only ever use once is kinda steep. I am also planning/hoping to re-use the valve-cover gaskets as they seem to be in good condition. Thanks.

Thanks all. I'll post up when I get the carbs off again (sigh). Since I'm going to check the valves while I'm at it, is there a good source for the tool that's used to change out shims? Does anyone here have on that is loaned out to forum members or the like? I've got access to shims, but not the tool. Looks like I can purchase for around $60, but I'd rather not for a tool I'll likely only ever use once. [Edit - I'll start a separate thread about this to avoid hijacking my own thread, LOL]

Patch, thank you for the replies. I think we are miscommunicating. If that is my fault, I apologize and I will try to be clearer in my meaning. Based upon the tests I performed and my observations, I DO NOT believe I have any problems with spark in cylinder #4 (or any other cylinder). I have good spark in each cylinder under all conditions. I mentioned that I swapped out #3 & #4 coils (without physically moving them from their mounting bracket) - this was only done to confirm that there was no issue with the coils that my other tests had not revealed. I mention pulling the plug wire off of #4 while running. My point in doing this was to see if there was any effect on the running of the engine by pulling spark to #4 - and there wasn't. I mentioned an earlier post that I could get #4 to fire under some odd circumstances involving removing power to the California emissions solenoid. In thinking about it further, perhaps this was creating a richer condition that allowed #4 to fire properly. Just a hypothesis. I wonder if, instead of spraying carb cleaner into the tops of each carb (which apparently is of the non-combustible variety), I should squirt fuel into the tops of each carb and see how they react. I wonder if that might get #4 to combust, which would comfirm that FUEL is the missing element. As for the ports on carb #2 - mine has 3 visible ports, not 2. Of course one is the inlet for fuel, another is the drain. Mine has a third port located towards the left rear corner of the carb. I've seen such a port on pictures of members here with '83 Ventures. Maybe this is also something that is on the California models too. Or maybe a prior owner installed a set of '83 carbs on the bike - I really don't have much on the history of the bike or why anyone would do such a thing. This seems unlikely, in any event. I expect this may be something (else) that is specific to the California models.

The bike has 4 individual coils. I tested voltage for all coils a few weeks back and all were right on the money per the service manual. I even tried swapping the wiring for coils #3 & #4 to see if the problem would move, and it did not. I also verified good spark (at different rpms) using a spark gap tool (thanks for the tip about this - got a Motion Pro one for cheap on Amazon). Sprayed area around plug wires and coils with water bottle per recommendations here and no problems observed. I did move the boost sensor hose from #1 to #2 . I also blocked off the port that was sticking out of the bottom left rear corner area of carb #2 . Previously I believe this was just routed to the charcoal canister. I doesn't seem to draw any vacuum, as shooting it with propane made no difference while running, nor did blocking it with my thumb. In any event, it's capped now. To clarify (since you asked about it) when I synched the carbs, this was NOT the port I connected my gauges to - i connected the gauges to the ports on the intake manifolds. To you point though, there are no vacuum leaks and air is ONLY entering through the airbox. As for decarbonizing the cylinders, and the higher compression figures, I am inclined to wait on this for now. I have read through your prior posts and instructions on high compression numbers and the processes for eliminating the excessive carbon. That may well be warranted for the overall health and running of the bike, but it doesn't seem directly related to issues I'm having with cylinder #4 . The highest compression numbers (after my most recent test) are on the left side of the motor, whereas my problem cylinder that does not appear to be firing (or at least not all the time), has the lowest compression. It seems to me that I need to prioritize the issues specific to cylinder #4 , before turning my attention to clearing the carbon out of the other cylinders. But if my reasoning is flawed or my understanding of the facts is wrong, I am happy to listen. I know that 4 basic things are needed to support combustion in a cylinder - FUEL, COMPRESSION, SPARK, EXHAUST. From everything I've seen/tested thus far, I don't think compression or spark are missing. So that leaves fuel and exhaust. As to fuel, the carbs seem the most likely culprit. I suppose it is possible there's some obstruction in the header for cylinder #4 that would prevent/limit exhaust, but this seems unlikely. I guess it's possible that the exhaust valves are not opening fully/properly. For that matter, I suppose the intake valves may not be opening fully/properly, thereby limiting the fuel needed for combustion. As for the prior carb work that was done, my friend/independent motorcycle mechanic is the one who serviced them. He took them down, cleaned in ultra sonic cleaner, checked passageways, measured floats, inspected slides, and installed the 4 new K&L carb kits that came with the bike when I bought it. He also bench synched the carbs. That said, he fully admits this was his first time going around with a set of carbs quite like this setup and allows that he may have missed something. Not having done the work myself, I can't really offer any more details than that. I think where my head is currently leading me is to pull the carbs again to see if anything is wrong. Patch, I know you stated this would likely be needed in one of your first responses, but I really did not want to hear that at the time. I'm thinking it would probably be good to check the valve lash (and look at the condition of the lobes!) too while I have good access. Again, if I'm heading in the wrong direction, or there are some easier things to try/check first that I haven't already tried, please let me know.

I did as you suggested and checked compression again with a warm engine (can't swear that it was warm the first time I tested compression. Results were similar to first test, with #4 being the lowest. Here were my readings: 1 = 190 2 = 195 3 = 182 4 = 178 I again verified spark in all 4 cylinders using my new spark gap tester (thanks for the tip on that Patch). Spark looked the same on all 4 cylinders. Same thing with a known good sparkplug. Tried this at varying rpm's and good spark was maintained in all cylinders, including troublesome #4 . Plug leads definitely connected properly with positive engagement of the plug top. I also inspected the plug condition. #2 & #3 were brownish, and perhaps just a bit lean. #1 was surprisingly rather black and sooty. #4 was black and a bit wet looking, but definitely not soaking wet. I backed the pilot screws out 1/8 on #2 & #3 , and turned #3 in 1/2 turn to try and compensate for what I was observing on the plugs. Plugs were cleaned, tested, and reinstalled, except I put (yet another) new plug in #4 just in case. Upon your suggestion, I opened the top of the airbox and Squirted carb cleaner into each of the 4 carbs. The effect of spraying into cylinders 1,2,3 was that the rpm's would drop, then take a few seconds to recover to their original level. Spraying into the top of #4 had no effect on engine rpm's. I repeated this being methodical about it, each time with the same result on #4 . Again, tried pulling off the plug wire on #4 while running and it had no effect at all. This was true no matter what the rpm's when I pulled it off. I tried to check at different throttle positions, but again, no change. I could not really check at half throttle or beyond, as I could not hold it in this position since the engine would still go to redline and beyond. The engine definitely spins up, but it seems to be just 3 cylinders that are making any power. I did another road test yesterday to see if I could learn anything further. Again, the bike does have power and will spin up - I had it up to 110 mph and it got there reasonably quickly. I can both hear and feel that it's hesitating or struggling some at about 1/8 throttle. This was consistent in gears 1-3, though the rpm range where noticeable was lower for each successive gear. It was most easily observed in 2nd gear around 5000-6000 rpm. By 4th or 5th gear it was getting too hard to detect. I didn't bother filling up with gas again to check mileage, as it was clear that it was still not running right and going through gas much too quickly.

I was able to test the boost sensor using my Mityvac the other day in the garage and it appears to be working. I didn't go to the trouble of testing voltage, but it did hold a vacuum, and apply and releasing vacuum did make a clearly observable difference in the rpm's. That said, I did not notice any difference at normal idle speeds; however, when I bumped the idle up to 2000, then applied vacuum to the boost sensor, the rpm's went up to around 3000 or so as I recall. I was able to repeat this after multiple attempts. So I feel comfortable ruling this out as a potential problem.

Thanks luvmy40. Any approximate range in terms of psi I should use with the Mityvac? Been wondering what is "too much." I've also read that the boost/advance doesn't kick in until near 2000 rpm. Do I need to crank the idle up to 2k to do this test in order to get a meaningful result? Thanks.

Thanks for the reply Patch. Indeed, I am here seeking guidance and feedback from those more experienced than I. As for gaining a deeper technical understanding - I do so when I am able, while other times I rely on more direct instructions ("do this..." "test that..." "remove and replace this...") when the technical reasoning eludes me. Based upon prior testing (testing and swapping coils, service manual checks of TCI connections, measuring spark gap), and replacement of plugs, plug caps, and fuse box, at this point I am prepared to mostly rule out my problems as being electrical in nature. Do you agree? I can't fully rule out a screwy TCI without being able to swap in a known good one, but I don't think that's the problem. As I do more reading, I see that it is also possible there could be an issue with the so-called "Boost Sensor," which could be either an electrical or mechanical failure. I spent some more time testing and tuning in the garage last night, with a focus on the carbs. - the "volume and ratio issue" I believe you were alluding to. Here's what I did and the results: -Tested for vacuum leaks with propane - none discovered. -Checked fuel float bowl levels after getting the bike/carbs level - this took several tries for me to get the hang of it, but all 4 seem to be within spec. - around 16 mm below the center-mark on the carb bodies, give or take .5 mm. This actually surprised me, as I expected to find one or more the float levels to be high, as the source of the bike using so much fuel. -Synchronized the carbs using my brand new 4-gauge carb synchronizer set (Woo Hoo more new tools to play with!). This was performed at 1000 rpm's, per service manual. 2 of the carbs were off a fair amount, but not outrageously so. Other observations while working on it last night: -I periodically checked the cylinder temps using my contactless temp gauge (measured at the same point near the exhaust side of each head). Cylinder #4 was still the slowest to heat up. Even after the engine was fully up to operating temps, #4 was 25-35 degrees cooler than the other cylinders, but definitely hot (around 180 was the highest I believe I observed on #4 ). -I had the bike running around 2.5 hours while I tested and tuned last night - mostly idling, with some occasional revving. I started with a full tank (only 7 miles since filling up) and by the end of the night the fuel gauge was showing only a half (!!!) a tank of gas left. -the vacuum line coming from the boost sensor is connected to the manifold vacuum port on cylinder #1 . From what I have read in other threads, on the MkII bikes, this is normally connected to the manifold port on cylinder #2 . I can't really see why this would make any difference, but I did come across at least one post where a member said this caused his bike to run poorly. -Sniffed the exhaust fumes on both sides and while both smelled of unburnt fuel, the right side smelled a bit stronger. That said, I don't regularly sniff exhaust fumes, so this may not mean much. -Observed an open port on carb. #2 . This appears to be the same port that '83's used to connect the boost sensor hose to (from what I've read here). Does this need to be capped, or should it be connected to anything? Plugging it with my thumb didn't seem to make any difference while running, and propane near it didn't cause rpm's to go up. I believe it went to the charcoal canister previously (which has now been removed). Action Items: -I need to pull the plugs again and see what they look like now. -Test boost sensor & relocate vacuum line to manifold port on cylinder #2 -I also need to take the bike out and check MPG again, but unless I discover a faulty boost sensor, I don't expect I'm going to see much difference based on just the carb. synch I did. At 22 MPG, I'm a looong way off the typical 38-42 MPG I'm reading elsewhere on the forum. Suggestions for next steps or things to look at beyond the above action items?

Thank you for the encouragement and vote of solidarity! Progress continues. Fuse box has been replaced with newer style blade type fuse holder. Performed "Shotgun" cleaning method on carbs 3 & 4. Pilot screws removed from #3 &#4 and noted that there was no rubber oring for #4 - or at least I could not find/recover it - so I replaced the missing oring with what I hope was the correct size. Bike mechanic friend helped me perform a leak-down test of all four cylinders performed and they looked good - 3% or less. We also disconnected the California emissions stuff and capped the inlet going into carb. #2 . Synchronized carbs (using single gauge that we moved back and forth to different cylinders). Adjusted the seal of the air filter (foam on bottom of filter was completely missing), and got the airbox seated correctly (that was pure fun!). Pilot screws adjusted out to 1.5 out. So, what was the result? Well, the bike is running better than it ever has since I've owned it. While that it not really saying much I suppose, it spins up quickly and clearly has a LOT more power now. After working on it Saturday night in the garage, the throttle was super responsive and it sounded terrific. It idles nicely at just over 1000 rpm's. That said, it's not all positive. It seems to be "over-fueling" and getting terrible mileage. I took the bike out on Sunday for an extended shake-down ride. I filled the tank and headed out for some back country roads to romp on it some. It was mostly good, but at different points (hard to identify specific throttle position, RPM's) when I would give it a lot of throttle it would give a slight hesitation and not take the throttle as it should, then recover and pull strong. My suspicion is that it's getting to much fuel at those times. More telling was that only 85 miles after filing up, the bars the fuel gauge were all gone and the fuel warning light had even stopped flashing (steady red). Calculated the MPG as only a little over 21 MPG. Yikes. I filled up with another 4 gallons of fuel and this time set to see if my riding was having an undue influence on fuel economy. I headed for the interstate and made a loop around the city on the beltway going around 70-78 MPH (70 MPH limit). After doing another 80+ miles of mostly interstate, the fuel bars were gone again and I gassed upon with another 4 gal or so of fuel. I calculated my mileage this time at just over 22 MPG. Ughh. Now close to home, I turned off on a side road and really opened her up to see how it would respond, since the sluggishness at some points was quite noticeable. Well, it seemed to like that kind of treatment (even had the oil light kick on), as the throttle response seemed great for the next 2-3 of miles until I got home. I wanted to keep riding and continue experimenting, but alas, I had to head home. So, I'm not sure what to do next. I'm thinking I'll get it running and check for any vacuum leaks in connection with disabling/disconnecting the Cali emissions stuff. Maybe pull the plugs again and see how they look after Sunday's ride. Beyond that, I'm not really sure what to think as far as why it seems to be over-fueling. Assuming that is in fact what I'm experiencing. I don't have any clear fuel line or the necessary adapters to check fuel levels in each carb., but maybe I need to get some. I did finally breakdown and ordered a 4-carb balancing gauges so I can check the balance again.

Update & New Data. I may be onto something here. Last night after I pulled the #4 plug to inspect, I cleaned it up and reinstalled. Then, I decided to fire it up just, well, just because. Here's where things got interesting. But first I have to provide some details on what I believe(d?) to be a totally separate issue relating to the fuse box. Bike still has the original fuse box with the glass (really Yamaha?!?!) fuses. For a while now I have had a problem with one fuse holder marked "Signal." It is the second from the bottom. Among other things, this circuit includes the digital dash functions and the tachometer. The problem is that one of the fuse holder prongs was weak and would not firmly hold the fuse in place. This would cause the circuit to drop out and (maybe) come back sporadically. Just touching the fuse would using get it to work again. I had previously attempted a repair of the fuse holder with some solder and it seemed like the fix had worked. But then this past Saturday when working on the bike I noticed the issue had returned. I also saw where a small hole had been melted into the fuse box cover over this problematic fuse prong. The bike would still run when the circuit was not completed (fully warmed up and without choke), but the rpm's noticeably went down. I did not experiment further on Saturday and instead just got the fuse to complete the circuit and focused my attention back on cylinder #4 . Upgrading the fuse box to a "blade" style was already on my future "to do" list once I got the bike running right. So, now back to where things got interesting last night. As I said, I fired the bike up last night. Cold start with full choke and the Signal circuit was working, as I had tach and digital dash functions. Bike started right up, as it usually does. After running a couple of seconds, the fuse lost its contact, having the following effects: tach stopped working (expected), digital dash stops working (expected), and ENGINE RPM'S WENT UP TO AROUND 2000 AND HELD THERE. This surprised me so I began to experiment some. I touched the fuse causing it to make contact again, and the dash and tach came back, and THE RPM'S IMMEDIATELY WENT BACK DOWN. Breaking the fuse contact again (I forget if I did it on purpose or if it did it on its own again) and the rpm's raced back up to 2000 or so and sounded pretty good (still on choke mind you). So, I then I pulled the plug wire on cylinder #4 to see what would happen and........[drumroll]..........I could hear the cylinder cut out and rpm's drop! Pushed the plug wire back on, and rpm's went back up. I tried this a couple of times with the same result! Fiddled with the fuse to complete the circuit again and the rpm's dropped, and when I pulled the plug wire on #4 it made absolutely no difference. So, then I tried to get the bike to warm up a bit and run off of choke. I didn't have time to get it fully warmed up (it was late, wife and daughter in bed, neighbors to consider, etc.), but I did get it enough to be able to get it mostly off of choke. I couldn't really rev it up much because of the late hour. What I noted though is that rpm's in general were now slightly lower with the Signal circuit open, and that if I pulled the plug wire on #4 the bike would stumble and possibly even stall. With the Signal circuit closed and functioning, the bike then idled a bit higher, but pulling the #4 plug wire would make no difference at all (which is the symptom I have previously always been observing). I would like to go back and start the bike and let it fully warm up and see how it really runs with the fuse removed from the Signal circuit (and possibly adjusting the idle up a bit). Hopefully I can try that in the very near future. What I do not know or understand at this point is just how this "Signal" circuit relates to the running of the bike. I did look at a wiring diagram on my phone and see that in addition to the turn signals, horn, dash, and tach, something called an EAND relay a California Only Air Solenoid (remember, my bike is a Cali model) are also on this circuit. Doing a little research it appears the EAND is for the anti-dive forks. I can't find any more info on the Cali-only air solenoid. In any event, I do not know how these last two items function and interrelate to the running of the bike, but they are certainly on my radar now as potential causes. Thoughts? Suggestions? Information about operation and testing of the aforementioned EAND relay and air solenoid? P.S. - I ordered a new 8-slot fuse block last night and will be upgrading once it arrives.

Fair point. I guess vacuum could/would be the same irrespective of combustion (unless of course there's no compression - but I've got decent 175 psi showing in #4 ). Interesting that we're both chasing issues in cylinder #4 . Your very low reading of 60 psi is obviously concerning. Not being familiar enough with these bikes to really know, I wonder if adjusting the valves on that cylinder will be enough to bring the compression back up to within specifications. That's a looooong way to go though. If not, maybe you've got valve/valve-seat issues. Hoping not, for your sake.

Ahhh, ok. Now I understand.

Well I just pulled the plug on #4 and it's all black and carboned up. Not wet, but it's had since Saturday to dry out I guess. This is a brand new plug installed just before the last two rounds of wrenching and trying to diagnose. I'll try and attach some photos but I'm not really clear on how to do that. As for hearing #4 or not, I'm pretty confident I'm not just overlooking it. When I pull a plug wire on any of the other cylinders I can hear the effect and see the rpm's drop on the tach. Pulling the wire on #4 has no such effect.

"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.

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.

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.

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

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.

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.

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!

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.

Gary is great to deal with. I have an older version of the Ampli-Rider installed on another bike that I've been using for probably 10 years to mix signals from GPS, radar, and music (either MP3 player or Sirius). Mine has the remote volume control hardwired on both ends. It works well, though I do get some whine/noise that I believe is caused by the GPS, despite adding a noise filter. Some years ago the unit stopped working, so I emailed Gary about it. He had me send it to him, whereupon he fixed it and sent it right back with terrific communications. I originally had the volume control mounted in a dash fairing that I drilled a small hole through just so the threaded part under the knob stuck through and then was held in place by the retaining nut on top (with the knob in place above that). Worked well and was a clean/neat install. I later moved it to just underneath the left switch pod and attached it with two-way tape for automotive applications. I love it there as the knob extends out just enough that I can use my index finger to easily raise/lower the volume without ever taking my hand off the grip or eyes off the road. Good product and good maker/seller.