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Hi All,

I have a 1995 Big Bear 350. Last year it started sputtering somewhere above idle. I'd say 1/4 throttle. Doesn't seem to backfire. Just sputter. Enough that you can barely use the machine. Idle is fine though.

Went through everything I could think of as well as some other stuff I got off another site. Still causing the problem. Anyway, here's the list of things I've done/replaced. Not necessarily in the order I did them in...

1. Had a Chinese carb, so rebuild original. Same problem.
2. Bought another Chinese carb. Same problem.
3. Fiddled with carb settings (mixture screw at bottom of carb, slide level c-clup). Same problem.
4. Dumped old gas. Replaced with new non-ethanol gas.
5. Petcock was leaking. Replaced with new one.
6. Replaced fuel lines and fuel filter.
7. Unplugged carb air inlet line.I think it was an air inlet. It was about the same size as the fuel line and near the top of the carb
8. Cleaned and inspected inlet tube between carb and head.
9. New air filter
10. New plug
11. New coil
12. New CDI
13. New stator/coil pickup
14. Checked valve clearances. They were good.
15. Checked compression. About 75 psi. Thought this was my problem. Replaced entire top end.
16. Checked battery, tester said it was good.
17. Disconnected kill switch.
18. Disconnected brake light (not sure if the brake handle had some kind of rev limiter).

At this point, only thing I haven't changed is the plug wire. I almost thought replacing the fuel line/filter fixed the problem, but once I rode it, it didn't. Don't really see what else there is for me to replace. It seems like the plug is giving decent enough spark when I tested it outside the cylinder. Of course that doesn't mean it is working correctly at higher rpm. Seems almost like a fuel problem, but that's the first thing I looked at and the entire system (except for the tank) is new. Really getting disgusted at the money I'm throwing at this. Is there anything I'm missing?
 
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