This afternoon, I finally got a chance to test out my the clutch mods I recently installed on my P650. I went to the back of my neighborhood where I do all of my top-speed testing on a (deserted) flat, asphalt road approx. 1/3 to 1/2 mile in length.

CLUTCH MODS:
I recently did 3 things to my clutch including the Top-speed Primary Clutch Mod (shaved a total of .070 off), installed a brand new P700 belt and installed the EPI maroon primary spring. NOTE: The only reason I replaced my old P700 belt was b/c it had 1,000 miles on it and I wanted a fresh one for the 2005 XC racing season.

RESULTS:
1) At take-off, the belt engagement is the same as stock (no stall effect) and I like that.

2) I noticed that the motor revs a little higher thru-out the powerband (at any given speed) due to the Maroon spring. So far I like the maroon spring, but I will hold off on giving an opinion on this spring until I get a chance to spend more time testing how it performs.

3) My top-speed was improved from 66 mph to 69 mph for a total gain of 3 mph. For what its worth, I also noticed that I get to the same point in the road at 2 or 3 mph faster speed as compared to before these clutch mods (so I'm guestimating that I gained a little acceleration as well as top-speed).

MY GOAL:
My goal was to gain 4 mph so that I could finally reach the elusive 70 mph barrier (on a flat road). While I did not reach it today, I'm hopeful that eventually I might be able to improve to 70 mph with this same set-up as the CVT belt stretches and the maroon spring breaks in with usage.

Just so everyone is aware, I apparently have one of the "slower" Prairies b/c it only did 58 mph when brand new (after the break in period, of course) whereas several other folks on these forums have reported mid-60s when brand new. I'm happy that my mods have taken me from 58 mph when new to 69 mph today. Not a bad improvement overall.

In any case, I'm thrilled that I was able to gain 3 mph for the $220 investment that I recently spent on my clutch ($120 on machine work, $75 for the new belt and $25 for maroon spring). By comparison, I spent approx. $250 for the Dyna CDI and also gained 3 mph in top-speed, and I'm very happy with both of these investments.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

MIKEY... did you have the 25" Bear Claws on during this testing ???

 

If he had those on, he could take em off, reduce weight, and hit that 70. [img]i/expressions/face-icon-small-happy.gif[/img]

 

Yes, I had the 25" bearclaws on during testing today and also in my previous testing when I hit 66 mph on the same exact road. I should also note that all speeds reported above are on my speedo and thus, they are probably off a little. I know I should use a GPS for accurate top-speed testing, but I don't have one yet and besides that, I think the speedo does an adequate job of letting me know approx. how much improvement I'm getting from each mod I try out (in this case, I gained about 3 mph).


PS - Before I did this clutch mod, I could do 66 mph with my same set of 25" bearclaws according to the speedo. With my 22" tires installed (which are approx 30 lbs lighter and 13.6% smaller in diameter), I could hit 65 mph (when adjusting my speedo read-out for the smaller diameter tires). So in a nutshell, I figure that I only lost about 1 mph with the 22" tires installed and I was very happy with that result (based on the improvement in handling/cornering that I get from these 22" tires). If the same result holds true now, I should be able to do about 68 mph with the 22" tires.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]