I own a 2000 500xcsp. I have 4500 miles on this sled. In the fall I took it to the dealer to get the clutch cleaned and serviced. He took it apart, cleaned it an reassembled it. ( no new parts) This year while driving it I have found a considerable decrease in top end. Approx 10 miles per off the speedo. Any ideas why? (I have tested on hard pack several times)

Have you checked compression? Maybe you need new rings? Your up there in miles so that is where I would check first if it's not the clutching?

How's your RPM's
Replace your springs in your clutches?
It's possible the bushing or your buttons in your secondary need some attention!!






Blue

It's also possible the secondary spring was reinstalled in the wrong hole. There are five to choose from, It normally goes in the middle hole. You could lose about 200-300 RPMs that way. I would have your dealer check it out, unless a buddy has a clutch press and experience.

Jack in Ohio

I completely rebuilt the secondary this fall. New spring, new buttons.
The only thing that the dealer touched was the primary and just to be cleaned.

I also heard if the bushings in the secondary are warn, it causes the secondary bind not allowing it to fully shift out properly. If I'm not mistaken you remove the helix and spring and side the movable sheave back and forth on the shaft, if it doesn't slide smoothly the bushing could be warn.

Also, how tight is your track, did the dealer adjust that to. She should be good and loose.

It ran 10mph faster at the end of last season and she slower this year?
I'm thinking about mileage, and wear, but if it ran alright before (last Fall) than it's something maybe the dealer did without knowing it. Tight track will kill the Top End.
Blue

Remove and completely diassamble the VES assembly.
Check for leaks and cracks in bellows or broken bellows nut etc.

I had same prob just recently. Valve would hold vacuum using finger test, but would not pull top rpm or speed. Took assembly apart and found broken bellows nut was allowing bellows to leak at WOT.

try the belt put a new one on and see what that does before going to the motor thanks and ride hard

I would check my primary and rebuild it , that got me more top end this season, also maybe your track is so stretched that it affects top end.

Explain to me the bellow vacuum test on the ves. I will try this tonight. I rebuilt the secondary but I am going to pull apart and check it out. I installed a new EPI yellow spring in the fall. I may try to decrease the spring tension here
by one hole as it feels like I have lots of tension on the secondary now when changing belts. What do you think?

Ace - It may be prudent to replicate last year's set-up and use that as a baseline. Put the original spring back in and test. Very easy and fast to eliminate that variable or not.

Jack in Ohio

I Pulled the secondary and reinstalled last years spring. Its somewhat better. I also found when I pulled the air box off there was excessive fuel in the bottom and also into the upper foam. I have always noticed some fuel there but not this excessive. Reed Problem?