Bought a new to me '95-ish Timberwolf 4x4. It's super clean which is unusual for a quad of its age in Alaska. BUT, because it wouldn't keep running worth a crap, my dumb *** didn't try to ride it or put it in gear; I just pushed it onto the trailer with the help of the dirtbag seller who obviously knew all along that it had bigger problems than just poor running. I figured I would overhaul the carb, change the fluids and have a decent machine for the wife to occasionally ride.

Got it home, and messed with it some more and found I was able to keep it running a little by playing with the throttle. Which was when I discovered that when I put it in gear, it wouldn't move at all. I assumed the centrifugal clutch was bad. I just finished replacing that clutch plus the shifting clutch (which made sense while I was in there). Got it back together and no change. So, something else is obviously broken. I didn't see anything else that looked unusual on that side while the clutch cover was removed.

So, before I start digging further into it, I thought I would inquire here about other known weak points in the drivetrain? I am thinking output shaft or transfer case currently, but I haven't really gotten into that part of the manual yet.

 

Can you tell if transmission is taking gear? Did you install one way bearing correct?

 

It seems to be going in and out of gear. When I had it apart, the one way bearing appeared to be doing what it was supposed to. I never took the bearing out of the clutch housing. Next time I mess with it I am planning to remove the transfer case. If I don't find anything there I will maybe take the clutch cover back off, but I don't really expect that to be productive.

 

Can't remember if the Timberwolf is the same as other Yams of that era but 90s Yams did have a weakness in the rear axle, as many owners don't notice when the LH rear wheel bearing fails. This puts all the weight onto the crownwheel and the splines start to wear. Soon they let go and crownwheel spins but axle doesn't. With bike stopped but in gear, take the rear diff filler plug out, push a screwdriver in, roll bike forwards, if you can feel the crownwheel going round, fault is further forwards, if crownwheel isn't moving round but axle is, you have found the fault. Used to be expensive, we found a machine shop that would make Big Bear axles from billet, still cheaper than Yamaha genuine ones.

 

Just noticed your title says 4 x 4 so above doesn't apply, as front end would still pull the bike along. So, fault is in either a clutch, gearbox, or transfer box.

 

That's correct, but it is still good information for future reference. Thanks.

 

Good news. Before tearing deeper into it today, I fiddled with the shifters some more and I figured out there isn't anything actually wrong with the drivetrain. As you're probably aware, the T-wolf has a separate shift lever for reverse, which can only be shifted with the transmission in first. This had gotten stuck between being in reverse and forward. I hadn't messed with it much since the lights were indicating that it was not in reverse, the lever had seemed to be all the way forward, and the transmission had seemed to go up and down through the gears. It took some fiddling but I was able to get it all the way into reverse, and then back into forward. After that I was able to ride it a little and it seems to shift OK. I still have to rebuild the carb, which at least I knew about when I bought it, and having new clutches isn't going to hurt anything.