1990 yamaha big bear 350
Was running fine when i purchased it. suddenly had trouble starting and when it did it had a lean runaway or wot. replace carb. and still has same problem. checked intake gasket and it’s good. air fuel screw does nothing. what’s the problem? any ideas?
also carb does not pull fuel from tank.
going to disconnect throttle cable and see if it helps

 

Have you checked the inlet manifold for splits or and cracks? Sounds like an air leak between carb and engine to me.

I had exactly the same problem but on a mower last year, turned out to be an leaky inlet gasket (looked perfect but wouldn't seal so fitted a new one and all was good).
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might just throw a new intake manifold at it. gonna give it another shot, check the float level, disconnect the throttle see if she runs

 

Have you tried?

 

Seems no.

 

Now it’s not even starting, i posted a new thread and a guy said it could be timing. i put new the carb to engine manifold with some gasket sealer. Been busy. Gonna check if timing jumped today. Also the fuel thing was cuz i barely had anything in it. I changed the spark plug so i’m gonna see if it’s that too

 

Have you found any solution?


 

Nope, timing looks good. just checked spark and compression they look good as well. maybe i got a faulty carb? any ideas?