New here and to quads completely. Picked up a 1986 lt250r and the guy told me it had been sitting for about a year and most likely the carb needed to be cleaned to run. So I drained old gas, put in a new spark plug. Took out the carb cleaned it out. It will kick over with the throttle all the way open than will idle perfect for a few minutes. Than all of a sudden will revs all the way up like I'm pinning the throttle all the way down. If you kick it into dirt get it comes back down and idles fine again. And can rip around fine.I've been told possible air leak? Just looking for any suggestions before I spend money at a shop.
Thanks,
Noah

 

Spray carb cleaner around the carb/boot area. If it changes the rpm's there is a leak.
Worst case it could be crank seals.

 

Possibly the float sticking or junk in the tank cutting off fuel. When a 2-stroke starts to lean out, the revs go up. My Quadracer always did that when it ran out of gas.

Definitely check for air leaks too.

 

Thank for the quick replies guys, just sprayed carb cleaner around the carb/boot and nothing. So I checked the oil the store gave me and it was 2 stroke outboard marine oil....so I dumped the tank got some Lucas 2 stroke at the store put fresh gas and oil mix in and it's running great. Appreciate the help
-noah

 

Can't imagine outboard oil causing a problem unless it was mixed wrong.

Good that you got it going, quadracers are fun machines!

 

Yea I didn't think it would have made such a difference either. Maybe there was some crud blocking the gas tank or maybe I didn't have enough gas In it and it was choking for gas

 

Enough fuel helps.