1985 trx 250: cranks and idles fine. As soon as you hit the throttle just a little and the motor revs up, it takes about 10 sec for it to come back to a normal idle… can someone tell me what to adjust???

 

Check to make sure that the slide is in the carb is clear of any debris and moves up and down smoothly. After that, try adjusting the throttle cable by the throttle, it may be too tight. When the throttle is not being used it should have a small amount of free play in it to make sure that it closes completely. If it doesn't have that free play, it can cause problems. Hope that helps.

 

Check the throttle cable, after that pull the carb and clean it 100% inside and out, make sure the choke works properly then idle it to operating temp and adjust the idle to around 1200 when warm outside and about 1400-1500 RPMs when cold. Hopefully that works if you have any questions feel free to ask. Also make sure the throttle isn't sticking.

 

I have done everything. Throttle is adjusted, carb is clean, choke works fine. Air filter cleaned and oiled. Any other ideas?

 

Is this the 2-stroke or the 4-stroke. Either way, check for vacuum leaks. Spray WD-40 around the intake and cylinder base gasket. If it is a two stroke, it may also be a bad seal.

 

Fuel mixture or needle jet is in wrong clip groove

 

I did not think of that. I tore down the carb and cleaned it but did not touch the needle. i guess it may have been like this when i bought it. it was not running when i bought it.. Thanks, for you help!!!!!