CR125R shifting problems

[RCR YZ125]

its defiantly shift drum/shift forks and there is a possiblity of a stripped out gear.

also there are small lock collars with taps that break sometimes and allow the gears to not move. either way split the cases.

the upside is its a 2 smoker.

[VintageGuy]

That's true, since it's a two stroke it would be easier for me to attempt it myself, or at least with some assistance.

Thx,

B

[fbr]

Bob, Do not split the cases yet. I had a very similar sounding problem with one of our '07 CRF250R's and this bike shares many parts with the CR125. The Drum Shifter is recessed inside the end of the Shift Drum Center. It engages the shift drum with two sping loaded plungers that keep outward pressure on two pawls. On our bike, one of the plungers was stuck in the hole that it is supposed to slide in and out of. The plunger spring was fully compressed and so there was no spring pressure on the one of the pawls. The tansmission would not shift in that direction, only in the other direction using the pawl that was functioning normally. I popped the plunger back out and everything worked fine. I reassembled everything a couple of times after some deburring and so forth but the problem reoccured until I replaced the spring, plunger, pawl and, I can't find the receipt to verify, but, I think I replaced the Drum Shifter also. This would be the part that has the two holes that the plungers and springs sit in.

[VintageGuy]

Mark,

Thanks for the tip. I'm going to pull the right side case tomorrow to see what I can discover with all the moving bits.

Bob

[fbr]

Bob, I just figured out how to insert a picture. Look at the schematic below of the Gearshift Drum on the 2004 CR125R. Take the clutch off and I think you can then see the two pawls (11, 12) on the drum shifter (9). The pawls should be held in position by spring (15) pressure. If one of the plungers (13) is stuck than the pawl will be sitting in there loose.

[DirtyD]

+1 on the previous poster. That was great advice... it's nice to see someone who knows what they are talking about for a change. Once you get the right side case off (not just the clutch cover) you can try to work the shifter while you watch the shift drum. Move the rear tire back and forth a little at the same time to help the bike shift. Does the shift lever move up without any resistance? This is almost always a sign that something has broken outside of the center cases, and that's always a good thing. Good luck.

[punkinrider55]

yup it seems like a lot of bikes are using that type of shift drum now with the tabs and springs..i just did an old 89 Suzuki LT250 rebuild top and bottom and they use the same thing...also i did an 02 cr450r top and bottom with the same shifting design..good luck..and i personally don't think its a gear..i think its in the shifting fork/drum..

[VintageGuy]

Wow, excellent advice and a schematic view as well. I haven't yet pulled the right side case off. I've been spending all my time off this week working on my new trailer.

I could see one of those spring loaded pawls once I took the clutch off.

Hopefully today I can get to it, after a drive up to Santa Rosa.

Again, thanks for the help!

Happy Thanksgiving,

Bob

[mxdad100]

Looks like you're becoming QUITE the Mechanic !

[VintageGuy]

Hey Rob,

If I can manage to repair this without taking it to a shop I might have to almost agree with you.

Bob