2003 Yamaha Wolverine Misfire

[ncgator]

Hello. I acquired this machine as payment for a debt, so I don't know a lot about it.

First, I had no no electrical functions at all. battery would not take a charge. New battery and reconnect a grey connector at the front of the machine took care of that. Now it starts, idles fine, but misses and backfires as soon as throttle is opened, with parking brake engaged.

An acquaintance who claims to be a motorcycle mechanic recommends changing the air filter and spark plug. I don't have a dealer close, but a local auto parts store is ordering them for me.

[DirtDemon]

A new air filter and spark plug are never a bad idea. If the quad has been sitting for a while, then there is a good chance that the carb is gummed up with old gas. You may want to take it apart and clean it really good, just to be sure. You mentioned that it sputters and backfires when the parking brake is engaged, does this happen when the brake isn't engaged?

[ncgator]

Hello. I thought I would follow up with developments, in case someone else was experiencing the same symptoms.

I disassembled the carb, cleaned, reassembled and installed it. I now have good idle and no missing during acceleration or off-idle sustained speed. I haven't actually ridden it yet, still putting all the plastic and racks back on.

I have a slight backfire as the engine returns to idle. Just once in awhile. Does anyone know what normal cylinder compression should be? I got 150 psi, with the engine slightly warmed up.

Thanks

[Stoopidbot1]

I'm thinking you are good. The backfire on decel could be a small jetting issues or a simple air leak. If it's not doing it bad and every time I wouldn't worry about it.