Need Help With RM 125

C

Chriss

Hey everyone, I have a 1983 Suzuki RM 125 2 stroke that I've had for about a month. First of all I cannot tell if my clutch is bad or if my carb is tuned incorrectly. In regards to the carb I think it runs rich. I have oil dripping from the muffler and it starts first kick almost every time with no choke. I also seem to have a loss of power at mid to high rpms, bike won't pull very hard ( I was riding today and it almost died when I gassed it quickly). When this happens the engine makes a different noise, it gets louder and kinda sounds like it's redlining but I know it's not. How do I fix this?

The clutch seems to be causing power loss too. Like if I pop the clutch at high revs in 1st the bike will pull a little harder but not even enough to get the front wheel off the ground. And I have to admit (I know this is bad), I did have oil in the trans that had friction modifiers in it for a week or two but it is changed now.

Any help is greatly appreciated. This was bought used and is my first dirt bike.
 
SRAD97750

SRAD97750

Moderator
Staff member
Welcome! Post some photos of that beast!!!
I am pretty sure it's just a jetting/float issue. I would pull the carb and clean it, set the float and try again.
-BIG DAN:thumb:
 
O

ossagp

Sounds like you are going to learn a lot in a short time. Dripping exhaust does indicate that it is rich. The float may be sticking and or need new parts. I can about bet it needs setting, which is free and easy. If you cant find the stock setting in a manual or the internet, get back to me and I can tell you how to do something useable. check the low speed air screw after you set the float. (clean the seat and the jets including the needle jet and holder while you are in there. looking at a schematic on bike bandit will help, if you don't have a manual.

As for the clutch, you need to take that apart, get some calipers and start measuring the plate thickness to see if that is an issue and whether it is worth it to try to clean those plates up and reuse them. You already know that your "nothing to gain" starts didn't help matters. I hope you learned from it.

Taking them out and cleaning them with 200 grit or so sand paper on glass and washing them off with brake clean may help. If they are burned unever or past the acceptable point you are spinning your wheels to try to use them. Save, save, save. Owning one even when you use the clutch right is not cheap. An older bike usually costs as much as a fresh one by the time you are done, but you can do it the installment way.
 
2strokesteve89

2strokesteve89

Yeah Ossa is right, you will learn quickly about carb tuning, I wouldn't be surprised if you have a lean needle setting also, by your comment that it dies or bogs when you gas it, also make sure it has fresh gas in the tank before you get too far into this.
 
2strokesteve89

2strokesteve89

Either way, but he should at least address the rich condition first, it may be more clear if there are other problems once the fat is trimmed off the carb.
 
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C

Chriss

Thanks for the input guys. I've also noticed that I often get fuel coming out of the carb overflow so I'm guessing by valve isn't working correctly. My air filters are pretty dirty too, do either of these contribute to the problem?
 
SRAD97750

SRAD97750

Moderator
Staff member
Chriss:
Thanks for the input guys. I've also noticed that I often get fuel coming out of the carb overflow so I'm guessing by valve isn't working correctly. My air filters are pretty dirty too, do either of these contribute to the problem?
Click to expand...
Overflow is an improperly set or worn float needle. Re adjust and clean the air filter. The clogged air filter can also cause you to run rich. -BIG DAN:thumb:
 
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