High Revving 125SM

[witttom]

Ok... I hate to admit it, but I haven't ridden my 125SM since my "Southern Tour on a 125" trip through LA, MS, AL, and FL. As some of you may remember, I had achieved some new high speeds that I had not obtained before and was feeling more confident on the highway. I also developed an idling problem that I had seen before, but had gone away prior to this trip. I haven't been riding it, because it is way overdue for an oil change which I just haven't had a chance to do (nor have I snagged an oil filter anywhere yet).

In case you missed it:
http://www.mzriders.com/viewtopic.php?t=842

Anyway, I pulled it out of the garage yesterday evening and rode it 40 miles (one way) to a Two-Wheel-Tuesday "Bike Night" on the Eastern side of Cincinnati Ohio (I live on the far Northwest side of Cinci. Not a great distance by any means, but I did it via I-275 which is a very aggressive highway looping the outside of Cincinnati, notorious for some rather serious high speeds. Anyway, the 125SM did extremely well and I found myself occasionally passing other traffic rather than being passed, most of the time just going with the flow. On my return trip, I hit the rev limiter twice (in 6th) which was a bit startling in traffic.

So, as our RT125 buddy Dave Thompson has mentioned on more than one occasion, it would appear the the 125's continue to get "Stronger" the more that you ride them. That's how it seems with mine anyway. So, now rather than performance enhancements parts, I'm considering a 1-tooth smaller rear sprocket to maybe gain me just a tad more top end. Haven't quite decided yet (not sure if I want to give up any on the bottom end).

Oh, BTW... the idling problem seems to have magically gone away again. Go figure.

[DAVID THOMPSON]

hi
now your seeing why i call mine Mighty Mouse

the rev limit is 10500 rpm
and i went to a 52 rear ...it limits top speed to 70
but 95% of the roads here are 55 or less and its hilly

the carb is very fussy about the gas... it uses so little that any bad stuff
makes it get very upset

[rotus]

I'm running a smaller rear sprocket. I'm not sure what size as I bought it that way and haven't bothered looking at it. It also has a smaller than stock rear tire for better handling at the track, but I'm putting the stock rubber back on it for sity use. I was able to get to 80 indicated the other day on flat level ground. Something I've noticed about the bike is that at those speed, you develop an annoying head shake. Has anyone else experienced this?

[Drew]

Oh yeah, I've felt the head-shake! But then again, given the frame and suspension technology, and the steering head bearings, I figure it's just par for the course.

If it's really bad, check the rear tire alignment.