Tach variation at 30MPH

[hank]

Hi all,

I have a 2016 RsVector XTX with just over 7000 miles (purchased from an older gentleman @ 5800 miles).

I've had Yamaha sleds for ~40 years and this sled had noticeable clutch noise between 4-5k rpm. No noticeable performance issue, just a minor rattle.

I thoroughly cleaned the clutches but did not replace any components.

I just returned from a trip to the UP and didn't notice the rattle but now I have what feels like a clutch grab at slow speed on a groomed trail (~30mph). The engine rpm changes from 4000 to 4700 every 5 to 10 seconds or so but no noticeable speed change. If I speed up the oscillation stops but returns when I slow back to 30mph.

The belt/clutches work normally outside of the tach variation at 30mph (belt has ~700 miles).

Any thought on what the issue might be?

Thanks.
-Hank

 

[Norse]

Similar thing happened to a friend of mine. One of the weights had started eating into the side of a a roller, so it would get stuck.

 

[hank]

Interesting, I disassembled the primary when I cleaned it. I didn't notice any wear though. I have to travel to snow so my opportunity to investigate is limited. Seems like I should replace the rollers & weights and go from there. Thanks.

 

[Norse]

Clutch rattle is normal on these. I wouldn't be too sure about the rollers, but you could also check for wear on the ramps on secondary and whatever component slides on them. Check springs too. But if the RPM changes in a rythm it could be something electrical/mechanical giving the engine a power surge. Check spark plugs, air and fuel filter. Maybe even check if voltage is stable.