Hello, I have a 97 xt 600 Yamaha twin I just picked up and we went through the carbs. Cleaned them checked everything over all seemed good. Finally got some snow to ride and took the sled out and I noticed when riding you could hold the sled wide open from the line and it would pull very well but it would hit about 50-55mph and fall on it's face and have nothing else there. We brought it back checked the plugs (which were brand new) and they were super wet so we adjusted the needle in the top of the carb switch it in multiple different positions to try to lean it out a little bit but any position wasn't much different we we're able to get it running where the plugs started looking pretty nice but still nothing over 60mph. We re jet it from a 151.3 to a 146.5 and it was better but 70mph tops half throttle wide open is no different. Any one has any ideas throw me some opinions not sure where else to go with it besides maybe a clutch.
clean and inspect the clutches. they might be binding from corrosion or belt dust from over the years. without the springs in, everything should slide smoothly and free.
opsled
Active member
Yup, Unless you know all is good/right with the clutches you could be completely wasting your time on the engine.
opsled
s10mike
Member
Try switching to your spare belt
A couple of bucks
VIP Member
Chances are that there is more than a few bushings that are shot in one or both clutches. Disassemble them over the summer and replace w/ Genuine Yamaha bushings. I’ll bet the clutch arms have a significant divot in them as well.
After all, we are talking about a twin.
After all, we are talking about a twin.