Carburator Kits:

[Rob Swallows]

I had let my bike, (2005 Midnight Venture) set in the heated garage for four years with the tank full with mid grade gas and "Stabil" in the fuel. I'd ran the bike till it starved out and died. It was kept on a "Battery Doctor" brand maintainer the whole time also. I'd not brought it back out citing life in the way of riding, and the bike just wouldn't ride correctly and I was afraid of dropping it. I have now purchased a high quality low pressure gauge and have the front forks balanced and what a difference! The left fork on the bike will consistently deflect the original low pressure gauge about 3.5 psi lower than the right fork. With the new gauge, they are perfectly balanced. Anyway with that settled I have now begun to ride consistent and have run up about a thousand mile this past month. Besides the heavy feeling to the bike in general, I really like it.

 

The reason for the post is I have mid throttle response issues only since it was setting. I've ran several gallons of fresh gas though, and the current tank full has eight ounces of "Seafoam" in it. I've installed new NGK Iridium plugs, and ensured there is no corrosion in the plug wire boots. The bike starts and idles perfectly but in fourth gear at about 52 mph it is missing on at least a single cylinder. In fifth gear the speed is about 57-62 mph. Seemingly it's on the right side of the bike. There is also noticeable "cackle" from the exhaust I don't remember from a prior life five years ago. It has decent full throttle acceleration although nothing like I'd thought for a 1300cc engine and does not seem to misfire during hard acceleration. It is rock solid dependable and we are preparing for our first long road trip in 30+ years but I'd like it to run perfect before starting out. It is never a dead miss but rather something like a high speed carburetor jet partially plugged or restricted. More throttle application always brings it back to running on all four. Don't know if I should keep going, or tear into it as our trip is going to take place in early September.

 

Anybody market carburetor kits for these things? I've not ever been into this bike at all but have purchased a synchronizer set for them for preventative maintenance. I don't have a service manual or any literature except owner's manual but am going to order one. I'm wanting to change the fuel filter but haven't found it yet either.....

 

Any comments or suggestions are welcome.

 

Thanks,

 

Rob

[cowpuc]

I would start it up from cold, get it off choke as quick as possible so its not running on the choke circuit, dampen my finger tip with spit and spit check (like checking a hot iron) the header pipes right after starting it. See if you can detect a dead cylinder. If they all heat up at idle it should mean they are all firing. 4 years of sitting is plenty of time to have had a jet plug over from dryed fuel,, the mid range carburation depends on the low speed circuit to be open and clean in order to function properly - seems how its happening in that mid range and it clears up when the slides open the main jets I would suspect a plugged or partially plugged low speed jet.. This should show up on the spit test if it is.

Another good possibility is having a sticky slide from sitting. It doesnt take much gummyness from sitting to create enough resistance on the slides to keep em from sliding properly.. Removing those slide covers and checking the slides is a whole lot easier than pulling the carbs and cleaning em so I would do that first. You should also double check your diaphrams when you do this - pin holes in the diaphrams will cause what your talking about too..

Another thing to consider is how well these things run and how they perform on 3 cylinders. I bought the bike I just retired (her name is Tweeks) with 24k miles on her from a guy in Northern Michigan. She was gorgeous and ran when I picked her up BUT she just didnt have no real get up and go. After test riding her, I asked the guy how long she had been running on 3.. He did a double take and said he had put 5k on her in the last 10 years of her life and she had always ran like that - which he thought she ran perfect.. I told him I suspected a diaphram problem.. Brought her home, pulled the slides and found one diaphram completed seperated from the slide and pin holes in another.. Fixed it and WOWZY did she come alive!! Ran her out to well over 300k before picking up this last new one and retiring Tweeks..

Also might wanna do a quick read on here on learn the sync process, toss the gauges on her and see what she looks like.. Learning to and keeping those carbs in sync is a great way to keep your scoot happy. I have my doubts that syncing is gonna fix what your describing but its worth a try.. Just dont get her way out of adjustment trying to sync out something that aint sync outable,,,, if that makes sense..

[BlueSky]

An infrared thermometer available at Autozone or Harbor Freight might save your finger. I'm sure Puc can do it without burning himself but the thermometer will provide a little more information to us non-gurus.

[Rob Swallows]

Thanks for the responses guys. I have a non contact thermometer and all four are relatively close in temperature at low speed; i.e. idle. I suspect a clogged jet or diaphragm problem myself and I can get the misfire with a little harder acceleration from a stop than I normally run. With my normal acceleration it's not even noticed unless my wife is on the bike also. If I slowly accelerate through the given speed it picks right up.

 

Are the diaphragms under the black plastic caps and about 2.5" in diameter? If so I can pull those easily but would I be best served if disturbing them to replace? Being an 11 year old machine it might be a good idea? I'll do a carb synchronization as I was supplied an auxiliary fuel tank and the main tank will be removed so I can watch things. Where is a fuel filter on this bike if known? I don't think it's been changed as the original owner only changed the oil & filter.

 

Thanks for the help.

 

Rob

[Rob Swallows]

They seem to be all firing at idle. All four were about 96-99 degrees and after three minutes running at idle, all are in the mid 125 range. # four is the hottest at about 129 degrees. I'm going to ride it around a few minutes and reshoot the pipes which are kind of difficult to get a look at straight away due to the fairings and chrome covers.

[Rob Swallows]

Rode about six miles at easy throttle and they are all within 30 degrees of each other best I can tell. They look to be just over 225 degrees after idling about two minutes. Wish I had a tach to relay engine rpm of the misfire but I can believe it's a cylinder starving if the slide doesn't open. I've never had a bike with diaphragms in the past so this is a bit new to me. I can pull the diaphragms with little difficulty if they are under those covers but would want to have ready spares available as just in case. I've never dealt with the Yamaha dealership here in the Peoria area so know nothing about them. Are there aftermarket suppliers available?

[M61A1MECH]

OK these links may help, they are from the ventures website, there are some similar on our forum in the read only tech section.

 

Shimming the needles, http://www.venturers.org/Tech_Library/index.php?action=article&cat_id=002010&id=165

Carb Drawing, http://www.venturers.org/Tech_Library/index.php?action=article&cat_id=002010&id=163

Fuel Filter replacement, http://www.venturers.org/Tech_Library/index.php?action=article&cat_id=002010&id=275

 

The links may not open to the subject, if not go to their tech section for second gens and find the titles.

 

One thing I did on Venture once was to close the petcock and run the motor until it started for fuel, as you did when you stored it.

Disconnected the fuel line from the tank and added an extension to it. Ran the extension into a can of Seafoam and turned on the key so the fuel pump sucked the Seafoam up into the system and filled the carbs. I let that set for several hours (overnight) and then reconnected the fuel line to the tank. It was a bit had to start on the pure load of Seafoam, but it did and that seemed to clear out the issues I was having, which were slightly sticking floats and poor running.

 

Hope this helps.

[Condor]

One more thing to check just because.... The caps that are removed to sync the carbs. Check them for cracking?? Just siting around may have caused them to deteriorate.

[Rob Swallows]

Thanks guys. I'll follow suit with the suggestions and have plenty of "SeaFoam" in a couple of bottles for this task. I'll look into the carb diaphragms tomorrow along with maybe shooting the slides with some carb cleaner if they're accessible. I did notice a couple of little things that shouldn't be there; I removed the fake fins from the rear cylinders and there were two screw on brass caps/tips from a prior carb synchronizing apparently. I've never been into this engine so they have be left over from prior maintenance. I hate losing tools and I'm certain somebody wasn't none too happy about this.....

 

The rubber plugs that are to be removed from synchronizing, are they the ones looking like a bulb with a band clamp on them near the middle of the carb? Looks like they would be in a bleed air passage to me and you replace the plug with a hose leading to a manometer/gauge?

[mm482]

The vacuum caps are on the manifold between the head and the carb and yes they have a band clamp around them.

 

Do not run the engine with the fake fins removed, the rubber coolant plugs may pop out.

[Rob Swallows]

The vacuum caps are on the manifold between the head and the carb and yes they have a band clamp around them.

 

Do not run the engine with the fake fins removed, the rubber coolant plugs may pop out.

 

Thank you kindly. I didn't start the engine at all with them removed. I was trying to figure out how to change the spark plugs before realizing the tank needed to come off for most any kind of service. Before that, I didn't realize they were fake as never really looked.

 

I dug into that other website and found the procedure for synchronizing the carburetors with photos, along with a few other things, (great help) but it appears the website is no longer supported? It sure seemed like a nice asset for these type motorcycles.

[Rob Swallows]

Is it alright to remove the airbox above the carburetors and directly spray the slides with cleaner? I don't have anything apart at this time but the Mikuni carburetors on several of my Z1, and KZ 900/1000 Kawasaki motorcycles I'd done this to. What about removing the air cleaner elements and "fogging" the intake air path while modulating the throttle slides?

 

It does seem to want to run a bit better with the more use but while I have a bit of free time, I'd like to get it wrapped up and not look back.

 

Probably won't let it set again.....

 

Thanks,

 

Rob

[bongobobny]

Have you checked out OUR tech library for possible answers too??

 

http://www.venturerider.org/forum/forumdisplay.php?14-Second-Gen-and-Royal-Star-Technical-Library-READ-ONLY!

 

There is even a downloadable factory service manual in there for free.

[Rob Swallows]

Thanks, I've not really delved into the website at all. I'll get a look later today when more time is available.

[Rob Swallows]

Well, got a look into a bit of the website and appreciate the tip; quite useful.

 

Today I met the Yamaha dealer and very nice folks I'll say for certain. It may be a story for the "Pay it forward" category but their mechanic I actually know from a chance meeting alongside a highway several years ago when I was in the auto body business. I changed his daughter's flat tire a couple miles down from my shop in the pouring rain as she had infant little ones in the van and really didn't know how to do it. The spare tire in the Chrysler mini vans is under the driver and front passenger's feet and it must be lowered from inside the van and dragged out from underneath. As I was finishing up, the father drove up and that's how we met.

 

Anyway, he is not familiar with the Venture motorcycles as they are not that popular around the area but is very versed in the "V-Max" series. Going by his suggestions on what wears or gives trouble in those machines, and at his cost, I ordered four diaphragms, four throttle valves, and four base plate gaskets or "o" ring seals for the float bowls. He says it's clogged jets for certain and to remove the carbs, remove the base plates, remove the floats and needle valves, remove the diaphragms and throttle valves and clean everything with carb cleaner. Outward appearance is the carbs will not need broken apart for soaking requiring many more pieces parts to reassemble and adjust. It should be an easy job given no cylinders are actually dead. #1 , and #4 are definitely weak in comparison to the other two as verified with my Type "K" thermocouples and selector panel. Kinda hard to get these connected to read right on the pipes themselves but small band clamps holding the thermocouples did work.

 

Best part is what I don't use can be returned with no charge as they are common usage parts for them.

 

Thanks for the assist with this.

 

Rob

 

I'm about a hundred into the parts but am confident on the right track.

[bongobobny]

OK good luck!! There are other minor possibilities that may or may not be an issue. Depending on the mileage, you may need to adjust your valve clearance, but I personally thin your issues are carb related.

 

The Vmax uses pretty much the same engine/carb setup, just different jetting, and minor differences, so your mechanic is on the right track...

[Rob Swallows]

OK good luck!! There are other minor possibilities that may or may not be an issue. Depending on the mileage, you may need to adjust your valve clearance, but I personally thin your issues are carb related.

 

The Vmax uses pretty much the same engine/carb setup, just different jetting, and minor differences, so your mechanic is on the right track...

 

Thanks. I have barely over 13K on the clock and it ran fantastic prior to setting so long. It is actually getting better as I ride with the Seafoam cleaner intermixed into the fuel but it's taking a while.

 

Rob

[bongobobny]

Great!! I recommend 1 full can of seafoam to about 3/4 to a full tank of gas then drive it like ya stole it! Also a note, depending on how much gunk has built up seafoam treatments can foul out your plugs, but with your lower mileage it probably won't be an issue...

[Rob Swallows]

Great!! I recommend 1 full can of seafoam to about 3/4 to a full tank of gas then drive it like ya stole it! Also a note, depending on how much gunk has built up seafoam treatments can foul out your plugs, but with your lower mileage it probably won't be an issue...

The tank of fuel in it now is eight ounces to a full tank. I will dump the other 1/2 of this Seafoam container in the tank later this morning and fill up again. I've been riding the bike daily and it runs pretty good at full throttle. I do tend to run it right in the spot where it's troublesome, (57mph in fourth, 62mph in fifth) purposely to work that jet area of the carbs. Last evening I did notice some seeping around cylinder #1 carburetor boot and the rest are very dry. This is a first. The vacuum cap one removes to sync the carbs is soaked with a liquid drop hanging after a couple of hours riding so nailing it down so to speak. Also see evidence this area is an active drip onto the engine topside. Wish I knew how to post photos as I take several daily.

 

I just installed new NGK Iridium plugs late last week. The formers were very clean burning and looked to have many miles of service remaining.

[Rob Swallows]

# 1 carburetor is definitely suspect as the pooling of gasoline is consistent on this one. This wreaks of gasoline/Seafoam mix. The bike is smoothing through it's power band but still struggles upon light acceleration. I've not pulled any plugs or hoses to ascertain if they are full of gasoline, but an uneducated guess at this point leads to a plethora of fuel flow problems so will wait for the parts to come in and plan on tearing into it. I don't notice any flooding and no smoking, but the exhaust pipes do have minor carbon "sooting" which is not oily at all. There is quite a bit of cackle upon deceleration but it varies in intensity and is not consistent in tone. I'm suspecting there is a fuel problem in a cylinder on each side of the engine as the two rear cylinders were a bit "colder", (via thermocouple readings) than the front two. I've thought about plugging the AIS but really don't want to get off the beaten path at this point. I know there is a problem and don't wish to induce additional variables into the equation at this time.

 

Given these new findings I'll revisit my new buddy at the Yamaha dealership to discuss further. I may wish to order additional parts as these may go in the submersion bath for cleaning. The methylene chloride based cleaner I use is not very friendly to some plastic parts so will need to discuss further to avoid destroying anything.

 

Getting kinda tired of kicking myself in the hindquarters given it's my fault through negligence, and ready to get the subject behind me.

 

The more miles I put under me, the more I like it. I even get compliments from the guys whom ride Harley-Davidson bikes also which is vastly different around here. It's all good however.

[videoarizona]

Rob, most of your cackle upon deceleration is coming from the AIS system and the very lean condition of the carbs as set by the factory for emissions. My PO totally took out the AIS system. But I agree...leave that alone for now.

 

Sounds like you are getting very close. Maybe only one or two carbs have mis-adjusted floats or stuck floats. I don't think you have a "plethora" of fuel problems...just a couple.

 

First, I would look at your carb diaphrams for pin holes, etc..These are easy to get to and a sticky slide or leaky diaphram can cause all sorts of problems.

 

Second, the joints between the carbs and the intake manifolds. Make sure they are snug, not leaking and not to tight. Spray carb cleaner in these areas with engine on and see if any change in rpm.

 

My ideas here are to get the obvious ruled out before you tear into the carbs.

 

Once into the carbs I would go straight to the floats. Two of them might be misadjusted allowing to much fuel or even sticky.

 

 

I'm out of ideas at the moment. Keep us posted what you find...

[Rob Swallows]

Thanks for the support. I too believe the problem is/will be easily isolated once I have parts available and in front of me. I don't tend to half a$$ repairs on anything so if I find wear, the will be replacements. I don't mind the cackle at all if it's normal and will leave that AIS alone at least until this misfire thing is figured out. Really liking the bike so far once I got over the heavy weight on the tank feeling at low speed thing. I'm going to tighten the steering head bearings when it's down as it just "falls" into a turn right now and is easily off center at low speed.

[Rob Swallows]

Thinking I found something significant:

 

I had the bike running at idle and I'm laying flat on my back in the parking lot listening to the music of the pipes and observing the bottom of the carburetors on the left side. This is after I've wiped clean the carburetor best I can which supplies cylinder #1 and removed all the boots and hoses needing removed to do a carb sync finding nothing wrong with any. I just happened to be looking at carburetor #1 when a drop of gasoline falls from what looks like a drain port in the float bowl right down onto the top of the engine. I stick my finger up there and sure enough, liquid gasoline from this drain port, (I suppose)? It looks like there is a socket head drain valve for shutting this off? I've not touched it and hope someone will chime in on this finding. Regardless it probably shouldn't be dripping any fuel which is laying on the top of the engine. I don't have an allen wrench long enough with me to reach the seemingly valve to tighten, or close it so will get to it later today when back home.

[bongobobny]

Sounds like a bad seat on the needle valve...

[Rob Swallows]

Agree. Pulled carbs off this afternoon and removed float bowl from #1 . Clean inside but a white film exists probably from the additive, (Seafoam) over the past couple of tank fills. I pulled two diaphragms and slides not able to see anything wrong with them, but will replace diaphragms all the same. I'll await the carb kits ordered earlier before tearing anything further apart as it's going to be a few days with the weekend and holiday. The airbox above the carbs was loaded with an oily mess also so going to check the air cleaners to see if they're plugged and clean this plenum. I've never looked at the elements in the past so need to teach myself how to disassemble the airway path to get to the elements.

 

It's always something for sure.

 

Rob