problem

[number5]

Just did a complete engine rebuild. Bearings, crank, and piston. About two weeks before tear down when I fist start the motor cold it would rev up high like its leaned out. If I pulled the choke it would not change anything. I used carb cleaner to look for air leaks and it did not change rpm. My bottom bearing went so I did a rebuild. With down time I took the carb apart and cleaned it out. I did not change the jets. Just took them out and cleaned them. With all new motor and clean carb I start it and same thing revs to the moon. I have v force 3 reeds that are fairly new. Once it does warm up it idles fine. After break in I look at my plug and its black. I just dont seeing changing out the slow jet because it didnt do this before. I just dont have a clue where to go from here. Im thinking of trying a different carb, reeds, ??? While its reving if I turn the idle screw in almost all the way it will idle down. This part is confusing too. Could it be electrical?

[GPracer2500]

Do a leak down test maybe?

[cdrookie]

the idle screw all the way in or the air bleed screw?

[number5]

air bleed screw. I think this is just covering something else up.

[86 Quad R]

i'd most deffinately do a leak down test on that mother. ;)

[C-LEIGH RACING]

When you put the carb back on the engine, did you put the slide back in the carb the right way. If you put it in backwards its half way wide open.
Neil

[Tubsy]

when i first got my 250r it did the same problem. I just adjusted the idle screw and it worked. Sometimes when its real cold out it will do it b.c my jetting is off since the bike is from florida where its warm and im in NJ where its cold. It doesnt do it anymore really once i get the re-jet i will know for sure if that was the problem.

[number5]

Originally posted by C-LEIGH RACING
When you put the carb back on the engine, did you put the slide back in the carb the right way. If you put it in backwards its half way wide open.
Neil



Its a d slide 36mm. I just raced it at bartow Saturday. Into first lap wide open long straight in 5th going into 6th engine stopped like kill cord was pulled. I put it down to 3rd popped clutch and it started. Then died again so I popped clutch again then it died. I stopped to the side to look at the motor thinking gas line or something fell off. I seen everything was intact so I started it and ran it for another hour with no problems. Nothing to do with this but Natalie, Borich, and Gee parked right infront of me early Saturday morning I was suprised to see them this far south. I though it was great Natalie was on his mx bike in a harescramble. I cought him eyeballing my laeger!

[cdrookie]

sounds like you have a fuel flowing problem. anything from a bad gas tank vent tube, blocked petcock screen, sticking needle and seat or dirty tank or carb bowl, maybe the float needs adjusted or replaced...

alot of pros head south to train during the winter, and the gncc opener isn't that far off. should've said something to natalie, he's one of the most personable guys you'll ever meet. i'm kind of suprised he didn't say something to you!

[joedirt]

Look in the tank for dirt. Blow out the carb make sure everything is clean. Make sure your reed cage has good gaskets and the intake manifold is good

[my88r]

Originally posted by number5
Its a d slide 36mm. I just raced it at bartow Saturday. Into first lap wide open long straight in 5th going into 6th engine stopped like kill cord was pulled. I put it down to 3rd popped clutch and it started. Then died again so I popped clutch again then it died. I stopped to the side to look at the motor thinking gas line or something fell off. I seen everything was intact so I started it and ran it for another hour with no problems. Nothing to do with this but Natalie, Borich, and Gee parked right infront of me early Saturday morning I was suprised to see them this far south. I though it was great Natalie was on his mx bike in a harescramble. I cought him eyeballing my laeger!

that sounds like a ignition problem. faulty Ignition coil or cdi. hows your ground?

[number5]

I checked the ground yesterday after thinking about that. It looked good and went ahead and checked it with my fluke. My cdi and coil are original. Im going to change both of those soon.

[CSR400EX]

just a thought, but crack your gas cap and ride it around and see if it cuts out. my 450 did the same thing, turned out to be a gas cap lol

[86 Quad R]

i hate vapor locks. :scary: