High RPm

So I know the right side is not firing due to the cold exhaust pipe. I have spark, fuel flow, compression, which leads me to believe the rigjt side carb is the problem.

I have cleaned it about 3 times now and used 2 cans of carb cleaner and 120psi air and little wire to poke passages.

If I put this back on today after the 3rd cleaning what could I possibly do next?

Diaphrams are good did the test.
Also carbs synced using paper feeler gauge
 
Well, from the looks of that right spark plug, my next guess would be the rings aren't sealing in the right cylinder. If the cylinder is full of oil, that can give a false compression test reading (good when it's really not). You've probably heard that if the compression reads low, add a spoonful of oil to that cylinder and re-test. If the compression goes up, it's rings, if not it's valves. In your case, if the rings are leaking badly and the cylinder has oil in it, that would be just like adding that spoonful. You can try putting some miles on it, things could improve. There's also a possibility the head gasket is bad, leaking internally between the cam chain tunnel and the cylinder. Have you re-torqued the head?
 
Sry that pic was the spark plug that was in it for who knows how long. I put a new one in and actually just check it as I put the carbs back on and started the bike.

Bike is running on both cylinders, however the right runs but is choppy. It's like fire,fire,fire ,stop,fire,fire,stop. I can hear it and feel It in the exhaust like this(sorry for bad explanation). So it's trying to run now which makes me believe this is solely a carb issue
Also the smoke is gone from the exhaust.

But when I pulled the right plug it was wet....I'm guessing gasoline, kinda smelt like it idk. Maybe too much gas is being poured in and not allowing for spark at certain times.

Also 5twins when I did the compression test I did it on a cold engine that sat over a day idk if they would show not bad rings.

Also have not done the head retoque.

Will post back with more progress on Wednesday- Thursday been busing working just had a 36hr straight
work.

One side note , with the carbs just off I noticed that I would move the throttle shaft left and right a tiny bit, however when I spary it wth carb cleaner around it, both sides, for the seals it doesn't change the rpms. So it should be fine even if it moves this slight bit?
 
Ok so I put new plugs in. For carbs i put new choke levers, gaskets and float needles, air/fuel needle. Re cleaned again and installed. This time I tried something and placed the left side float bowl on the right side carb. Guess what the firing has switched sides. Left is now choppy and the right is perfect.

I pulled the plug on the left side and found this
(the right side plug is perfect)

004.jpg
Carbon fouled so the air/fuel mix is off im guessing. But adjusting the air/fuel needle does not do anything.


So I thought it was still dirty and went threw the piolt circut and cleaned really good, I can see threw it perfectly with a light both way. BTW spraying carb cleaner in your eye really hurts, prob more then pepper spray I would know...

So right now Im at a loss...
 
You seem to have a bit of a "franken-bike" on your hands. It has a different carb set and maybe that has mis-matched parts on it. I'm thinking in particular, the float bowls. Did you compare them carefully and are they the same? You may have one correct bowl and one from an earlier model. The earlier type uses a different style of pilot jet (BS30/96) and feeds the air to that jet differently. Your '76-'77 bowls use the VM22/210 type pilots and the air should be feed across the top to them, like the bowl on the left below .....

BS38BowlTypes.jpg


The earlier bowl that uses the BS30/96 pilot feeds the air down an angled passageway to the bottom of the jet.

Since swapping bowls side to side moves the problem, it appears to be something wrong with the bowl. This is all I can think of unless the bowl passageways are damaged in some way. Maybe some pics of the insides of your bowls would help.
 
005.jpg

#1 is the one that is working when I switch it.

#2 is the non working.

They seem to be the ones for my model carbs.

Just switched the bowls again to see if it wasn't something else I did. Seems to be the bowl because I swapped again and the problem switched again.
 
Yes, they look like the proper bowls. How about the pilot jets themselves? Do they match? Are they both VM22/210 types? The metering orifice would be at the top of the jet by the screw slot. I think I can almost see that on the #1 bowl, not sure about the #2 bowl.

Pilots.jpg
 
If the problem appears to be in just the one float bowl, I would look very closely at that bowl. It may still have a restriction in the idle circuit of that bowl. Maybe the enrichener circuit.
Leo
 
Well, I'm running out of ideas here, lol. One last thing you could check are your float bowl gaskets. There are air feeds coming out of the main body on either side of the needle jet .....

PilotInletBS38.jpg


There should be corresponding holes punched through the bowl gaskets to allow that air through into the slots on the top of the bowl. One air feed supplies the main & needle jets, the other the pilot jets. Lay the gasket on the bottom of the carb body and on the bowl, and make sure the holes align so air can flow through.
 
Yeah i appriciate your help 5twins. I just replaced the gaskets and there allow the holes to line up with the holes in the gasket. I basically read a shit ton of threads on similar problems and tried everything.

As for the bowl idk how it could be any more dirty I can shoot carb cleaner and light source through the idle circut holes and looks similar to the other bowl.

For some reason I dont believe it is getting the fuel. Because the side that has the bowl on it I have to screw in the mix screw all the way(most gas) for that side exhaust to really fire decent.
 
Screwing the mix screw in cuts fuel flow. You're dealing with a true mixture screw on these carbs. It controls fuel flow, not air. But more correctly, it controls the fuel/air mix flow coming from the pilot jet. But even more correctly, it only controls about 25% of that flow. The fuel/air mix from the pilot jet exits into the main carb bore through 4 tiny holes. Three are clustered together by where the butterfly closes. These come directly from the pilot jet and are not effected or regulated by the mix screw. The fourth hole is off to the side and it comes from the mix screw via the pilot jet. It's flow is controlled by the screw .....

PilotOutletsBS38.jpg


It seems you have an overly rich condition going on with that bad bowl, the way it blackens the plug that way. Having to turn the mix screw in nearly all the way to lean the mix so it will fire decent seems to verify that. You need to figure out why this is happening.
 
Well, my next step would be to swap the jets from bowl to bowl. Maybe you got a mislabeled jet or something, one that's much bigger than it's marked as.
 
Well i figured that may have been a problem as I got new carbs parts today and installed both 27.5 jets inside that bowl. Had the previous one on and new one same result.
 
001.jpg

Well so Im fucked lol. I broke the float valve in the threads and I cant remove with a screw extractor.

My step dad tried to drill it out, and puncutred the aluminum carb a little bit at the bottom....this ruin the carb?

If so im in the market for new carbs if anyone has used....might buy new carbs not sure yet...
 
I've only just come across this world of woe :(

After reading the whole thread I was about to suggest that one of the floats fuel might be rubbing on one of the fuel bowls causing an over-rich mixture in the effected carb but now I see that you have another problem.

You might still be lucky to drill the valve seat out by using a 1/8th drill bit to carefully make a centred pilot hole then gradually work up the drill bit sizes until you can work the brass out with a pick. You need to drill at a very very slow speed like 60-100rpm and use a pillar drill or drill press for accuracy

I would not recommend using an easy-out on delicate brass and aluminium components, its too easy to damage them.

Once you have got the needle valve bush out you should be able to repair the damaged area with either
1 cold-cast aluminium
2 braze it with propane using silver solder, copper, lead or something like this
http://www.alumiweld.com/
 
Can't see the damage in your pic very well, but if the threads are bunged up enough so a new seat won't thread in, I would replace that carb body.
You may find one in the classified on here or a member may have one. Maybe Ebay.
This might be a good time to upgrade. The Kawasaki Ninja EX500 carbs are gaining in popularity.
Then there is the old standby. Mikuni VM34's.
Your bike, your money, your choice.
Leo
 

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