350x fouls plugs

[toyvette81]

it runs great for about 30 min's then the throttle starts racing by its self and sticking between gears, once it starts doing this it will start to backfire. then blow the plug within a minuite. i guess the slide in the carb is sticking, or the float is set too high causing it to flood? im sure i can fix it i was just wondering of anyone has had this same problem. & what they had to do to fix it?

[Dirtcrasher]

You most likely need to clean the whole carb by removing ever jet and squirting it with some good carb cleaner and check for air leaks too. Sounds like a typical nice easy fix.

[grundlegrabber]

Yeah, take the carb apart and do a good thorough cleaning. If that doesn't do it, you probably have an air leak somewhere. Also, check your jetting. Jetting too rich will cause plugs to become carbon fouled.

[toyvette81]

yeah thats how i got it runing was to clean the jets, the main jet was halfway clogged up and the low speed jet was all the way clogged , it would only run on full choke when i bought it, the carb is clean now, it has a stock 138 jet in it with a DG pipe i would think it needed a 142 jet but i guess not, something isint working right though b/c the ait mixture screw dosn't do anything thats why i think a slide is sticking or something

[MO350X]

Another board member had a plug fouling problem and the air screw did nothing.
He put in a rebuild kit (EASY!) and regained full control of the air screw, no more fouled plugs and MUCH better throttle response.
I doubt it's the float level, more likely the float needle could be shot.

CRUD IN THE CARB: It sounds like you're getting sediment of some sort into the carb..
You need to address that first.
No amount of rebuilding help if you keep ingesting sand/grit/etc..
Check the screen in the petcock and rinse out your fuel tank (rust, sediment in there?).

All of these remedies are EASY and you'll be shocked at the improvement!

JETTING: I had an open air box lid and free flowing exhaust on my old 350X and used a 142 jet at 400 ft. elevation. Worked GREAT!!!

[oddball3]

deffinately check the pilot jet again, souds like it is clogged again. find a fine wire that fits through it. A torch tip cleaner works great.