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View Full Version : 85 quadracer 250r engine trouble...Please Help



spartikus99
01-17-2010, 07:54 PM
Hi I am new to this site and I am hoping that someone can help me. I thought that the carb was dirty on the quadracer i just bought so I soaked the jets and cleaned everything up really good. I put it back in and when i first start it up it runs great. After the machine warms up a little it revs out like crazy. The only way to stop it from reving out like crazy is to choke it. Do I maybe have an air leak??? I just don't understand why it would only do this when it warms up?? I have read a lot of forums on here and everyone seems to be very knowledgeable. PLEASE HELP....Thanks for your time.:)

headache
01-18-2010, 07:33 AM
yeah it could be an airleak. Check your reed cage bolts to make sure they are tight. also check your intake boot for cracks. If all that is good, clean the carb again and make sure that your throttle cable isn't binding up.

spartikus99
01-18-2010, 08:06 AM
I dont think it is my carb......It cant get any cleaner. Everything seems to be very operational in the carb. My boot from the airbox and to the motor look really good. As for the reed cage bolts, I do not know how to access them?? I have never owned a quadracer or messed with the motor on one. Can u give me any insight as to where there are common problems with air leaking into the motor?

headache
01-20-2010, 12:36 PM
you do have the idle adjusted down right? I'd back it all the way out and see what it does. A motor can leak around the base gasket under the cylinder but that usually doesn't cause one to rev up like that...

corcope
01-23-2010, 06:29 PM
You have a airleak without a doubt. Its common on these old 2strokes if they have been sitting. If you turn your Airscrew all the way in and back it out just barely so it can start , start it and back it out till it will idle(but not over rev) then you can let it sit running while you spray the possible areas it could be sucking air. Spray all possible seals/gaskets it could be leaking from with break/engine cleaner. When it kills the engine youll know where it just sucked in the cleaner. Some people will tell you to build a leakdown tester... but that will cost you about $30 and takes alot of time.

The main spots to check/spray is: The reed cage seal, head gasket, base gasket, and crank seal(take stator cover off)

Email me if you have any questions i dont really ever check this site.

320
02-13-2010, 04:18 PM
The reeds on the 85 86 models are under the cyl.

350ex
02-15-2010, 05:27 PM
Ive got a carb and reed cage w boysen reeds if you wanna try it. $50 plus shipping its yours. Came off of a running quad.

DWR270
02-17-2010, 04:45 PM
Pull ignition cover off and see if the flywheel has any up and down play. If it does this means crank bearings are worn causing movement which will cause seal to flex and not seal out air.