1996 Yamaha 1100 Waveventure rough idle, dry cylinder

captain Gary

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Sep 9, 2009
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My middle cylinder appears to not be receiving fuel. Outer plugs are wet and middle dry. Required full choke and fuel to start and continual throttle to run. It was very rough. After shutting off, I had a smoky vapor coming from outer cylinders and nothing from center after pulling plugs. Center plug was still dry and outer plugs wet. Should I check for compression by pressure checking cylinders? Any help would be appreciated.
 

dannyual767

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May 15, 2010
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Re: 1996 Yamaha 1100 Waveventure rough idle, dry cylinder

It sounds like your middle carb's needle and seat may be stuck. When was the last time the ski ws run? If it was last summer, was the fuel stabilized before it was put up for the winter? If not, the gas might have gone bad or dried up and stuck the needle and seat together.

I don't think that I'd run the engine anymore until you fix the problem but you could pull the middle plug wire while the engine is idling rough and confirm that it makes no difference. Then you'd know for sure that the middle cylinder isn't firing.

A compression check is definitely a good idea.
 

captain Gary

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Re: 1996 Yamaha 1100 Waveventure rough idle, dry cylinder

The fuel wasn't stabilized after running last year. I failed to mention that I have an identical waverunner that turned over much faster using the same battery. Neither of my batteries made a difference in the cranking speed. I will try checking compression as soon as I can.
 

captain Gary

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Re: 1996 Yamaha 1100 Waveventure rough idle, dry cylinder

Thank you. I finally got back to the waverunner. Compression is 110 in cylinders #1&3, but 60 in #2. I sprayed carb cleaner in carbs, cyl #2 was still dry. I pulled the top end off and exposed the pistons, nothing looks damaged. any ideas?
 
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frozenokie

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Feb 4, 2008
Messages
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Re: 1996 Yamaha 1100 Waveventure rough idle, dry cylinder

I pulled the top end off and exposed the pistons, nothing looks damaged. any ideas?

Nothing may look damaged, but not the case with a 60# readout - 110# is around normal. You need a top-end rebuild. Don't run it anymore or you risk damaging the other cylinders. I have done top ends on Yamaha 1200's and they are one of the easier engines to rebuild.

On the fuel problem, I agree with dannyual767. I have had the same problems with different pwc's and a sticking needle, internal fuel filter clog, or fuel pump diaphragm is usually the culprit.

Use a fuel stabilizer and 2 cycle engine fogger in winter and you should be able to fire them up when ready to ride come spring.

Hope this helps and good luck on that rebuild.
 
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