RM 125 WIERD prob!! ..help!

Gid · Apr 11, 2006

ok i have a nightmare of a bike ...to say the least but the lastest prob is it won't start or idle. If i squirt a lil gas strihgt into the carb she starts right up so its obviously not getting enoguht gas in the mixutre
and onece it starts seh runs beautifly...unless you give anyhting under 1/8-1/4 throtlle or it dies. Now ive raised the float as high ahs shell go to let more gas in but it still wont start or idle it almost as if the idle circut is just non-existant .and yea the jets are pretty close to stock its jsut not sucking gas thought the ilde jet or something. any help would be GREATLY appreciated !! (the weathers getting amazing and I wanna take this beast out for once :bang: ..)

sick 96 250 · Apr 11, 2006

sounds like something is clogging the carb up. CLEAN it good, take all the jets out, floats, everything and give it a good cleaning with carb cleaner, re-assemble, put a new plug it and fire her up

Gid · Apr 11, 2006

thats the wierd thing I hwas havin prob's with my old carb ..same thing and this one is brand spankin new !! I'm almost beginning to think its not the carb ..???

dante · Apr 11, 2006

you most likley know this, but start with all the basics... Back the mixture screw out 1 /1/2... and check it off the list... check the reeds... maybe it is a jetting issue... It could be allot of things...

sick 96 250 · Apr 11, 2006

did you use the same jets frojm the previous carb? What jetting are you running. MAIN, PILOT, Needle CLIP, AIR SCREW turned out, etc

I think you should be around a 170-174 Main Jet, 48-52 Pilot, needle clipped at the 3rd position, Air Screw 1.5 turns out. Depending on your location could cause a big difference as well but if your around sea-level what i posted should be in the area. You could also be running lean and your not getting the fuel supply it needs on start up. See what setting you are at and let us know

Gid · Apr 11, 2006

im runnin 170 and 52 the clip is all the way at the top (I did this because I wanted to isolate the idle jet *cuz thats where the prob is ..I think* but it also will start if I tak e the air box off and manuly choke it by sticking my hand over the carb mouth so its gettin way to mcuh air and not enough gas

sick 96 250 · Apr 11, 2006

well put the clip back down to the 3rd spot and i bet you it helps your problem a lot, when its up that high you are causing a lean condition which is allowing more air in and not gas.

Fultoncm · Apr 11, 2006

If your using a carb off a '98 RM125, you'll never get it to idle. Hopefully that's not the carb you have. I had this poblem with mine and went with a year older carb...runs perfectly now.

Gid · Apr 12, 2006

itsa 94 rm and Im using a 95 carb

Gid · Apr 12, 2006

ok and hte idle circut is compleatly open , this is rly frustrating

sick 96 250 · Apr 12, 2006

what you mean its fully open? Did you move your need back down?

Gid · Apr 12, 2006

im sorry its not clogged, but yea it back down. Iv been playin around and its alllmost to that point of starting but not rly..grr

sick 96 250 · Apr 12, 2006

you put a new plug in as well? where is your air screw turned at as well

When was the last time the bike had a top end done to it? If your top end is worn it cause a lot of the same symtoms you are describing. Also look at your reeds and make sure they are not cracked or chipped and they are sitting flat on the cage with no gaps between them and the cage itself

Gid · Apr 12, 2006

ok plugs'new just put head gasket in ...although it leaks on the outside (its two o-rings) the outtehr one lets coolet trickle out hewn the bike runs ..kinda anoying as well but the air screw was at 2 now itat 1 1/2 and its almost starting so that looks promisng (it now smoeks when ya kick it so its at elast firen) btw thanks alot for your help so far !!

sick 96 250 · Apr 12, 2006

well if the head gasket or orings are leaking that is your problem most likely, they have to be sealed perfectly or it will cause a lean condition more than likely sucking air in where its not sealed off. To fix your O-ring problem on the head for the engine ( I'm Assuming thats what you mean and not the head pipe?) If its the head of the engine drain your coolant out of the bike, pull the head, take the o-rings out and put them in the freezer for a little, it will help you install correctly. if not you may need new 0-rings, but they must be sealed. no leaking of anything anywhere. Try that and post back, your prob also low on compression if the o-ring isnt sealed as well so it will help, you may need a new head gasket if that one is ripped or bad as well.

Gid · Apr 12, 2006

yea they are new but I didnt do the freezer thing ... I will try thaht thought haha heres to another top end kit :P but the inside ring is good (the one that keeps the coolant from the cylnder the outside one keeps the coolant from leaking out to the outside)

RM 125 WIERD prob!! ..help!

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