85 250r problems

[dm1tonram]

hey guys new to the forum, have a question.... my 250 has always run great, but recenty it will fire right up on 1st or 2nd kick but once it warms up is dies, and if i let it cool it will fire right back up and do it over and over again, i pulled the carb apart and it seems that the floats arnt stuck and everything seems good. and suggestions??

[dm1tonram]

nothin? need some suggestions, i no that i have fuel so it must be something electrical, anybody?

[Quadzilla2win]

Do a compression test. Remember to hold the throttle wide open with doing it.

[dm1tonram]

first of all thanks for the response, i didnt think anybody was going to. I dont think that compression would be an issue if it starts fine and it runs incredible for about 1 min or so then just dies while riding... correct me if im wrong though, im def not an expert thanks

[LTandRaptorider]

Originally posted by dm1tonram
first of all thanks for the response, i didnt think anybody was going to. I dont think that compression would be an issue if it starts fine and it runs incredible for about 1 min or so then just dies while riding... correct me if im wrong though, im def not an expert thanks

You are correct. When you lose compression, good way to tell this is the engine being hard to start.

Couple things to check. When the engine is cold, starting it requires a rich condition. Using the choke does this. Then as the engine warms, Needs a leaner mixture, more air less fuel. This is when your engine dies. Since your jetting hasn't changed, and you have checked the carb, I would suggest checking the reeds. How old are they? Check for missing reed petals, cracked, or curled on the the end. They won't seat correctly like that.

If this checks out, then time to move on to electrical. Coil and stator. You will need a volt/ohmmeter to check resistance of the windings in both of those. I don't have that spec in front of me. Maybe someone else has that. Or if you get to that point, post in here and will will dig out my manual. Sometimes when a coil or stator are going bad, as they heat up, the windings lose their resistance value and the engine quits. This usually won't happen for too long before the coil or stator just go kaput!

Another thought, how is the cylinder head gasket? Usually if that is bad the engine is hard to start though. Just throwing that out there to check since I don't know what you have done to the engine. Good luck, keep us posted. :cool:

[dm1tonram]

great, thanks for the response, the reeds dont have many hours on them, but they are a few years old, so ill check them to be sure.... Then i will move on to electrical, and i will let you know, thanks again for the help

[Quadzilla2win]

Compression tests and leak down tests are the first things i always have ppl check. With these old bikes it's always an issue. Do like lt250raptor said and check the reeds and test your electical equipment. I

f dont have one already get a service manual for specs.

stator =

black/white to black/red = 375 ohms

&

Blue to Black/white = 120 ohms.

Check your gap between the contact on the flywheel and pick up coil. use a business card. it should be a snug fit.

What are your jets sizes? (pilot & main and needle position) Stock carb? what air filter? what's your elevation? air box lid on or off? any other mods you've done?