1987 Suzuki lt250 4wd Erratic Idle

[Guillaume Cliche]

I have an erratic iddle problem i cheked all the air leaks i rebuild and cleaned the carb but it wont run straight it runs good but then slow and some times it stalls and its the second time the float implode 

[Frank Angerano]

Welcome to Quadcrazy @Guillaume Cliche That some implosion damage.  Have you had any backfires ? That reminds me of an old bike I had that the timing was off a bit and the valves were out of spec also.   The engine backfired and and did the same thing to my floats. I would start there and see if the timing is off. That would also cause an erratic idle. 

 

[Guillaume Cliche]

I didn't mention it but i also rebuild the head at the machine shop with new valves set the timing correctly change the cam chain and put a new gasket kit for the top end and intake gasket. Is a bad fuel pump can cause that or a bad vacuum hose ?

[Frank Angerano]

Sounds like you did the right job! The only thing I could think of was the timing unless your onto something with the fuel pump.   But the floats imploded to me equal a huge suctioning condition which could be the result of a poor fuel condition I would guess as if the engine is starving for gas.

But have you heard any backfire or as if the engine farted? Lol bad choice of words but best way to describe it!  Like it kicked back in the opposite direction ?

[Guillaume Cliche]

[Guillaume Cliche]

Yes it looks like the engine is starving your not the first to tell me that and for the backfires the first time i changed the float i remember seeing one you think that it causes the float implode ? Well i think the next step would be the fuel pump or inspecting the vacuum hose

[Frank Angerano]

Agreed. Def look at the backfire thing.  As far as fuel pump definitely check the pressure as well as flow. Try to use a small gas  tank and hose and gravity feed it to see how it runs maybe ? 

[Guillaume Cliche]

Good thank you frank for your advice 😃

[Frank Angerano]

Your welcome, I hope it helps you out in the long run.