need help with 1994 RM 125

[kwiktsi]

Hey guys/girls- I just picked up a 94 RM 125 last night that I thought just needed a good tune up, however, the problem seems to be much worse. I have not touched a dirt bike since 88, so the tech has changed some and I need to ask those who know more than I :).

Basically the problem the bike has is it does not want to pull into powerband. It gets up to that point pretty well, then just stops- like a bog or something. Even in neutral, it will not rev past a certain point. Now the details- the bike has a newer piston and jug (previous owner) and has 120 psi of compression. I went through the carb and it is all cleaned up. Upon further inspection, I noticed the rod that attaches to the powervalve linkage and goes down into the crank case was disconnected in the case, so I tore it down and hooked it all back up. Still does it. I also noticed that it is puffing smoke/oil out of the large breather from the powervalve location. I took the cover off the valve assembly and all three retaining screw for the valves were loose/out and the powervalves were loose. Tightened them down and the problem persists. I wonder if it is possible the jug got burned around the powervalves from them being loose and they are now leaking or if there is some kind of seal/o ring on them that could have gotten trashed from them being loose. Or would any of this not cause the symptoms I am having? I would like to know which direction to look before tearing it down further. Should I prepare for a new jug?
Thanks in advance!
Joe

 

[kwiktsi]

OK, after doing some reading here, it looks like 120 psi may be on the low side, my local shop told me it should be between 110-120 lol. I'm going to test again tomorrow just to be sure. I didn't think there was a compression issue, the thing starts on teh first kick every time.

Oh yeah, just thought of this- should also mention, the thing does not want to idle unless the idle screw is cranked all the way in and even then it is a bit low. I wonder if there is a leaking seal somewhere.
Joe

 

[kwiktsi]

Anybody? Also- I was thinking, anyone think it may be ignition related? I forgot to mention that if I ride the bike, 1st and 2nd will not come into powerband at all, 3rd and up do a little with the extra load on it, but it still isn't pulling right and it sputters here and there.
Joe