Picking your collective brains.....

[Jay B]

OK I have a coworker that has decided that he wants to get back on his bike. He hasn't ridden in 2 years because his bike is running kinda ragged. Its a 1986 Yamaha Virago XV 700 V-Twin.

He says that sometimes it will run and start just fine BUT once warmed up to operating temps starts running on only 1 cylinder. He has had it checked several times but the problem could not be found. He bought it new in 87 and in 88 had the stator replaced. After that it ran fine for a couple of years but after that developed this problem again. He replaces the plugs just about everytime it starts this and that hasn't fixed the problem. I'm thinking it could one of the following:

Bad plug wires or bad/loose coil.

My boss just bought one of those Ural knock offs with a hack and wants to get all the riders in the office together for a ride. My bud wants to go but doesnt trust his bike yet. I want to help him fix it as money for a mechanic is tight. Any of you brains out there have and other suggestions beside what I listed above???

[Anonymous]

Take a compression test JB I had the same situation with my sons buddy. One jug was extra low. ill bet rings are gone

[focus frenzy]

I'll bet that it is the back cylinder that is cutting out!
look to see if it uses one or two ignition coils, I think the virago has two coils, it may be a coil cutting out when it heats up.

[Don Lobacz]

There was a carb recall/update for those carbs. They would backfire and blow the carbs off. The service bulletin should be on the Yamaha fiche.

[Hoomgar]

If you put what Dom and Leon said together it kind of makes sense. Those v-twins are notorious for heating up the rear cylinder's. Maybe he rode it too hot one day many years ago and cooked the rings in the back piston.