93 Rm125

short and sweet. 93 rm125 brand new top end fmf fatty pipe, fmf shorty silencer, no airbox lid. Bike has no low end power. it will not take off from a dead stop . I have to roll it on a little hill and let the clutch out and pin it until it catches up to it self and then it rips hard mid to full throttle. i used fmf's website for jetting suggestions. please help.

put your stock muffler back on and see what it does.

93 has an exhaust valve, your linkage my be broken, and will cause that. pull the small cover on the r/s of cylinder and check the rod thats hooked to the valve, the little plastic clips break that hold it on. especially the lower one at the governer. you'll have to pull the case cover to repair it.

exhaust valve linkage should be fine cuz i just did the top end and it was fine when i put it back together. but if i pull that little cover and push the kicker down with my hand that linkage should move up and down correct? I will check it again though. if its not that what could it be. is using fmf's jetting suggestions right or should i change them. What should i be running? that was my main question but i forgot to write it. sorry worked all night and just got home.

exhaust valve linkage should be fine cuz i just did the top end and it was fine when i put it back together. but if i pull that little cover and push the kicker down with my hand that linkage should move up and down correct? I will check it again though. if its not that what could it be. is using fmf's jetting suggestions right or should i change them. What should i be running? that was my main question but i forgot to write it. sorry worked all night and just got home.
it should have a sping action up and down, push it down, it should bounce back, how did it run before the top end job? make sure your throttle cable is adjusted correctlly, and if anything on the jetting, i'd say the pilot circuit is a problem, probally too lean. how's the reeds?

yeah it springs back up. reeds are good, throttle is good. i have no idea

yeah it springs back up. reeds are good, throttle is good. i have no idea
pilot circuit in the carb, go 1 or 2 richer, timing ok?

Timing marks are lined up. they were off so i adjusted it but no difference. i need to pull the carb but havent had time. 1 or 2 richer would be a higher number jet correct?

Timing marks are lined up. they were off so i adjusted it but no difference. i need to pull the carb but havent had time. 1 or 2 richer would be a higher number jet correct?
yes, higher #, how did it run before the top-end job?

before i did the top end the compression was low and wouldnt kick start. i had to run it down the driveway and pop start it. once running it wouldnt idle and wouldnt take off from a dead stop. after the top end it starts first kick and runs a lot better but still wont take off or idle

go for the pilot jet, get a couple, 1 richer, 2 richer, where's your needle clip? 3rd is stock i think. try this go 1 rich on the pilot, air screw out about 1 1/2 to 1 3/4 turns and put the clip in the third groove from the top. if it isn't already. what kind of carb is it? look in the parts fiche and see what one it is if your not sure. there's alot of different needle choices too, so you can really fine tune it.

I decided to try something and it worked. i had no airbox as previously stated. what i did was i duct taped the airbox closed. bike now runs the way it should finally. but the bike is for sale and i dont want to sell it with the duct tape over the airbox cuz no ones going to want to buy it like that. i know from quads when u remove the airbox lid you need to rejet the pilot jet. what should i change mine to so i can remove the tape and have the bike run right. current pilot is 55. next choices up are 58, 60, 65. thanks for the help

i'd try the 60, w/ the airbox taped, shows it was too lean, so up 2 on the pilot might be just right, w/ no tape on the airbox. hope it works out for you.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now