I think when we accelerate, the belt move's down the rear clutch and up the front clutch, so for more top, the belt need's to ride higher up on the front clutch and ride lower down on the rear, Am I right here or wrong........

 

Danny;

You are right, about how the clutch moves, the problem is if you look at your front (primary) clutch, you'll see that the belt doesn't go all the way up. Just look at it, you'll easly see the marks left by the belt.

The reason for this is because of the angle of the clutch, as you go faster, the clutch weights force the two shelve together, squeezeing the belt makeing it go higher, but the two sheaves come completely together at the bottom before the belt gets to the top.

The answer for this is a wider and longer belt. That is why when the 360 - 700 belt is used you gain speed, they are wider, but not enough and can be forced higher in the clutch before the bottom of the clutch comes completely together.

WE milled a clutch at the bottom so it would close more and gained about 10 mph, and could have got more speed except the belt was not long enough. (Not Recomended)

I'm working on some ideas to get us more speed, without milling the clutches. One idea is to retro fit a snowmoble clutch, another is to lighten the primary clutch until your rpm go against the limitor, then add heavier clutch weights to bring it back down to your power band.

Why would you lighten you clutch, just to add more weight back to it you ask. The clutch weights swing in the clutch, as the clutch turn faster, they are swinging out against the moveable sheave, this is the force the makes the belt travel up, by forceing the moveable sheave closer to the fixed sheave . It is said that the stock weights produce over 2,000 lbs of squeezing force while rotateing. As the primary clutch closes (forceing the belt higher as it closes), it pulls the belt down in the driven clutch, changing the gear ratio as they go.

What we would be doing is, because the clutch weights are what forces the front pulley closer together, (2,000 lbs pressure), if we could add weight to these clutch weights, then we could add squeezeing force, (3,000 lb presure), this would make the belt go the the top alot quicker, more speed quicker. the problem with just adding weight to the weights is, any weight added to the clutch will lower your RPM's because it takes more power to turn a heavier clutch, even a few grams. By lighten the clutch first, we then could add that need weight to the clutch weights and improve pickup and top speed. We would gain the speed from when we added heavier clutch weights to bring the RPM's back down we would add just enought so our RPM's topped off at our peak Horse Power spot, 6500 when stock, or probably 6800 - 7200 if Modded. If you have added larger, heavier tires, you are probably not at your peak power now.

One of the problem with lighten the clutch is, where are you going to get heavier weights to bring the RPM's back down?
Sorry for being long winded, I just don't know an easy way to explain it.

 

This has been a very interesting discussion. I am not much of a mechanic, but I learned some things [img]i/expressions/face-icon-small-smile.gif[/img] (if I understand it all)...

Therefore, Would I be correct and thinking that the best set up right now for a P 650 provided you wanted max speed and decent belt life:

Holeshot module, stock secondary spring, and a p 360 or v 700 belt?

 

letcher, as far as we know what you said is correct.

I don't pull. I don't care enough about the top speed to have purchased a 360 belt yet.

I do care about driveability and longevity, so I stuck with the black spring.

 

I still have the stock belt, and I will wear it out before I change it. I am interested in finding more out about this pink spring, it sounds like it might be the plan.

but I am going to get rid of the black spring either going to stock or pink my ego hurts too bad from my buddy thrashing me.

I still have not got the modulator yet, I keep holding out hope for a CDI, or better solution, (I dont like the fact the modulator only kicks on under 3 mph) but I can't stand it much longer.

Gotta have the power. got to beat my buddy good.

 

Dalton has a great two spring clutch kit. On my dads p 650 I used my VForce belt , took the thinner shim out with the thicker one in and put the dalton springs in with ATRs on. On the speedo it said 72 and on the GPS it said 68 mph. It also got to 60 much quicker. It is other wise stock. I drew a black line up the drive clutch (primary) and after I GPS it the line was 1/8 inch higher up the side of the clutch.

 

The black spring works like crap by itself. Run the red and black together and your 650 will haul. I had the same problems with the black by itself. Put the red in with it and hang on. I had the same results with my kfx700. It doesnt like the black spring alone period. I need the pink spring epi is coming out with though. The red is a little much on the force.

Also somthing to check. On my prairie i had a problemwith the carb slide spring braking. It caused it to only be half throttle on the one carb. Put a new spring in and i went from getting beat by my bros griz to beating him by 6-7 lengths in 300ft. You can check it by moving the slides with your finger to see if the slides move freely. Also check the adjustment on your throttle cable. I gained 2mph due to a misadjusted cable.