bad low end power (audio clip)

[andrewbugg10]

Hey guys i have a 89 CR125R and it seems to have really lacking bottom end power, i know 125s are all topend but this sucks, if i get on the gas to fast it just almost stalls or if i go up small hills as u will hear in the video it bogs out and i need to keep it from quitting by feathering the clutch, i dunno what to do, my powervalve MAYBE is stuck open, im gonna check that , other then that my magneto crankshaft seal is blown so im doing that tommorow, i dunno what else to do

in the clip for the first half im in my garage reving and warming up then in the second part im at train tracks , 30 seconds into the second part im trying to get up a really small hill

the bike starts first kick ushally and reads 150psi

http://www.quadstop.com/files/biketest.mp3

 

[andrewbugg10]

but soon as i hit powerband or half throttle it flys like crazy as u will hear in the clip!

 

[fuzzy]

Man...The first 2/3's of that clip could be cut out!

LEAN! Like you mentioned, could be a leak, but I'd try richening up your jetting. Cold weather requires this! (Assuming your jetting was correct in warmer weather)

 

[elf]

You say your crank seal on the magneto side is leaking? thats more than likley your problem. If your seal is leaking it can suck air into your engine causing it to run lean.

 

[motoxforever250]

noman you need a stronger piston return spring and maybe some muffler bearings

 

[jasonent0613]

maybe (motoxforever250) should suck a wang.
lol

 

[IT1985]

Well, if the bike is running real hot, and you find aluminum speckles on the tip of the spark plug, chances are your bike is running lean. If you find chips on the plug, then you need to check and make sure your piston is damaged.

Put new oil seals in that sucker and rejet it, that should solve the problem

If you did all of this and its still running lean then check for air leaks near the reed cage and at the base of the cylinder. I always sprayed gum cutter or ether on the areas to check for leaks, if you do this and it bogs down and/or dies, then you have an air leak.

 

[harreng]

I know it sounds obvious, but have you checked your pilot jet? I use welding tip cleaners to VERY gently check for clear passage, remove and check all the holes. Pilot jet governs the smaller throttle openings, if it ran allright before, and you've done nothing else, it could be this.