[Merlin]

I have an 02 Foreman 450 ES that has been sitting for a couple years. When parked it, it was running rough. It would idle rough and miss once in a while. Sometimes causing it to stall. Upon acceleration, it would miss and sometimes "backfire" through the carb.

I have removed the carb and blowed all the jets and orfices out like the service manual tells. I also readjusted the valve clearance. They were about .010. I reset them to .006 as manual states. I have also flushed the gas tank out and put fresh gas back in.

This thing is driving me crazy! Now I'm not an atv "mechanic" to speak of, but I do know what I'm doing. Does anyone have any ideas? Could this be an electrical isssue? In the past, I did have a few wires chewed on by mice. I fixed them all, unless I have missed something.

I can get it to run only with choke on but it runs rough and will not accelerate.
Thanks!

 

[TRX2fiveO]

If it will only run with the choke partailly on then I have to say you have a clogged idle circuit. I know yoou blew out the jets and orfices but did you remove the jets? Did you use carb cleaner before? I would suggest that you remove the carb again, remove both jets and the pilot screw and any O-ring as carb cleaner will destroy them. you also could have a small crack or tear in the accelerator pump diaphram piston. Also you may have a bad carb heater. Some of the utility guys have more experience with these carbs, they should be along shortly.

Welcome to the forums

 

[submarine 300]

I would also say that the carb. Still has a little trash still in it somewhere. Also the timing could be off a little.

 

[shadetree]

yep..i agree..carb jets are stopped up..go back through it..and pull the jets..clean them out with a wire from a wire brush..nothing bigger !.

 

[Fastas]

yeah i agree carb issue

 

[Helmut]

Yeah, I agree. It sounds like the carb still has some debris in it somewhere. Also, make sure you check the rubber vacuum piston in the top of the carb. It could have a hole in it and that would cause it not to want to accelerate, because it wouldn't raise the needle.

 

[Merlin]

Thanks for the help. It actually was the idle jet plugged up. Initially I just blew everthing out, but then went back and took all jets out and looked through them. The idle jet was clogged almost completely shut. I cleaned it out with a torch tip cleaner. Now it runs much better. Thanks again for the assistance.

 

[tomgodd]

Glad to hear you got it fixed!!! Welcome to the Family!

 

[Helmut]

Yeah, glad you got it fixed.

 

[remington1000]

Glad to hear you got it fixed!!! Welcome to the Family!

Hi, I also had the same prob....I rebuilt the carb but no change..I ended up just replacing the carb...now it will crank and run percect..for about 30 seconds or so then will want to stall so i have to use the choke all the way but it dies after about another 30 seconds..clean fuel plug ect..Anyone know what I should try next ?

 

[shadetree]

Glad to hear you got it fixed!!! Welcome to the Family!

Hi, I also had the same prob....I rebuilt the carb but no change..I ended up just replacing the carb...now it will crank and run percect..for about 30 seconds or so then will want to stall so i have to use the choke all the way but it dies after about another 30 seconds..clean fuel plug ect..Anyone know what I should try next ?

welcome to the forums. this thread is very old. but to answer your question, start looking into fuel getting to the carb from the tank.