Please Help I have a 2stroke 400 i have replaced the rev limiter,the cdi,coil,reed valve and rebuilt the carb. When i hit full throttle the engine will rev up then bog down then rev up and down. When it bogs down it takes a few seconds then will rev back up HELP

 

fuel filter? crank seals? or air leak somewhere?

 

ok changed filter fuel and no air links not familar with crank seals

 

Float set to low, or not working properly. (Not flowing enough fuel)

 

Air leak I'm guessing as suggested,plus check behind front clutch for distorted or popped out crank seal. Usually if its a seal leaking this one is the main culprit. Can cause high revving and lean condition also.Plus check intake manifold for cracks or splitting. Spray a little contact or brake cleaner around the intake and cylinder and see it changes rpms also. OPT

 

sounds like you should do a leak down test as you may have a bad seal as mentioned. we have used starting fluid to test for air leaks as it would make the bike rev up by spraying the seal. this is kind of dangous if you don't know what your doing.

 

Great i will look at all that was sugested , also to clarify myself when i push full throttle is when the rpms are up and down. its like the rev limiter is kikking in but alot slower. it does not rev up by itself. Thanks for all your help

 

if it's acting like the rev limiter, then it's most likely electrical and not the carb. you may want to by pass the limiter just to check to see if it's still doing it by at least ruleing it out. imo