Running Rough. Here are the symptoms and clues - SOLVED

[john_berry]

I have a 1997 Valkyrie. It's not running right. Here are the symptoms. Hardly any exhaust coming out of the right side. Left is normal. so when it's running, the exhaust and sound coming out of each pipe is noticeably different. What does come out of the right side smells like raw fuel. When I unhook any of the plugs on the right side. It doesn't have any effect on the idle. Runs but idles a little rough weather I unhook a  spark plug or not. When I unhook a spark plugs on the Left side it makes a big difference. Sometimes even dies. The compression on each cylinder on the rights side are all around 165 lbs.


So here are the clues: It's getting spark, compression is good. Pipes on the right side are turning  black. Must be running lean or timing is off.  Ive also done the following work: Desmogged, rebuilt carbs, Installed timing belt. It's a California bike so I had to block off extra vacuum ports when I removed the extra vacuum lines. There were actually 12 ports that had to be capped. Two per carb.

My question is why doesn't the right side appear to adding any power. Why does the exhaust smell like raw fuel.

Could the timing belt be out of time?

Thanks

[Ricky-D]

If you can pull a plug on a cylinder and it has no effect on the running, you can say that that cylinder, it is not contributing to the running of the engine.

There can be several reasons a cylinder may not be contributing to the running at that particular rpm.

Since you say the ignition aspect of the engine is proper and working as designed, then the cause of your problem is not the ignition.

I would think the first suspect would be that in rebuilding the carburetors, changes were made that caused the problem.

The exhaust could be part of the problem if you are running aftermarket exhaust pipes.

But, mainly I feel it is your carburetors. That would be a good place to start. A synchronization would definitely be in order.

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[indybobm]

Have you synchronized the carbs since they have been rebuilt?

[john_berry]

Good thought. I will give it a try. I'll let you know what I find

[Pete]

"Pipes on the right side are turning  black."

I would suspect that one or more carbs on the right running RICH or flooding(float not shutting off).
Did you test the carbs on the bench with gasoline before reinstalling?

[john_berry]

Good thought, I'm very sure the floats are working. I did test on the bench, however I will recheck the floats to verify.

[john_berry]

I'm thinking more towards carb sync. That would cause it to idle rough. I think that it would also run okay once the throttle goes above idle and that is what happens. It runs okay going down the street. I guess I could pull a plug wire at 30 MPH and see if it makes a difference.

[Paladin528]

check all the boots on the carbs are seated properly.  also check the intake o-rings.  This can make a mess of things.

[john_berry]

Thanks for the help. It was the carb sync. All good now.