My son and I are working on a Suzuki '00 RM125. It ocassionally pops out of gear under full throttle, and sometimes you have to play with the lever to get it in gear. (particularly 4th 5th and 6th).
We took off the clutch and side cover and inspected the shifting mechanism closely. When you spin the drive shaft by hand and shift through the gears; you can see that the shift drum doesn't always rotate as far as it should for each gear (not suprisingly, mostly in 4th 5th and 6th).
Sometimes on it's own it will pop all the way into gear as you continue to spin the shaft. other times it won't.
We tore apart all the external (outside the case) shifting mechanisms, cleaned it up & put it back together. Everything looks fine, can't see any wear on anything, and it all. The rachet mechanism seems perfect. It as if the racket mechanism hits an invisable stop prematurely, 1/4 inch before it hits it's normal stop. The dentent is half way between it's stops too. (It seems like the detent spring is plenty strong, the shift drum has just not rotated far enough). If we werent spinning the shaft, I could see how the dogs not engaging would prevent it from shifting all the way. But we are spinning the shaft, and you can tell when it is the shifting dogs not engaging until it spins more, it feels different.
Spinning the drive shaft by hand, it does spin the countershaft after these partial shifts, but it obviously is not proper engagement .
You cannot shift further up until you shift down and go up again. It doesn't always go all the way into gear whether you shift fast or slow, deliberate or not deliberate.
The bike has never been torn down before, so it isn't that someone screwed up assembly.
Now we are assuming we must split the case, but my intuition says there is nothing wrong inside. But I see nothing obvious on the outside.
Anyone seen this before?
Thanks
Tom H
We took off the clutch and side cover and inspected the shifting mechanism closely. When you spin the drive shaft by hand and shift through the gears; you can see that the shift drum doesn't always rotate as far as it should for each gear (not suprisingly, mostly in 4th 5th and 6th).
Sometimes on it's own it will pop all the way into gear as you continue to spin the shaft. other times it won't.
We tore apart all the external (outside the case) shifting mechanisms, cleaned it up & put it back together. Everything looks fine, can't see any wear on anything, and it all. The rachet mechanism seems perfect. It as if the racket mechanism hits an invisable stop prematurely, 1/4 inch before it hits it's normal stop. The dentent is half way between it's stops too. (It seems like the detent spring is plenty strong, the shift drum has just not rotated far enough). If we werent spinning the shaft, I could see how the dogs not engaging would prevent it from shifting all the way. But we are spinning the shaft, and you can tell when it is the shifting dogs not engaging until it spins more, it feels different.
Spinning the drive shaft by hand, it does spin the countershaft after these partial shifts, but it obviously is not proper engagement .
You cannot shift further up until you shift down and go up again. It doesn't always go all the way into gear whether you shift fast or slow, deliberate or not deliberate.
The bike has never been torn down before, so it isn't that someone screwed up assembly.
Now we are assuming we must split the case, but my intuition says there is nothing wrong inside. But I see nothing obvious on the outside.
Anyone seen this before?
Thanks
Tom H