Newbeatle, when we machined the bottom of the primary,, the belt still didn't go out to the ends of the primary. that was because it bottomed out on the secondary first, it wasn't far from the top, but not out like it should as you would get in a snowsled..

nyroc, I think Alltoys said he built his clutch sheaves up, changed the angle of the hole sheave, I have never done that. I think I said that when we milled the bottom of the primary, to make it come closer together, that new angle at the very bottom made the belt slip.

I have also said I didn't recomend doing either. People have talked about going it, I say good luck, have at it.

To solve the belt lenght issue, someone take their belt off. Put a string it the bottom of the secondary and out around the top of the primary. This would be the length needed it the belt was wide enough to be forced to the top.

Post the findings.

 

I was thinking the other day about the concept of adding material to the movable primary sheave; to help push the belt up.

The added weight didn't make it sound too appealing. I wonder how much would need to be added; if it were to work?

Shotgun,

How much material did you have to remove from the base of the primary sheaves? I wouldn't think you would have to go that high to get better closure and not cause belt slip?

Are you positive that the belt bottoms out in your secondary?

 

SHOTGUN... Were you using the standard 650 belt or the same shape, but wider 360 belt, on the machined primary ??? the reason I ask, is I wonder if the wedge shape of the 700's belts, would work better on that machined sheave angle, than the standard 650 & 360's diamond shaped belt???

 

As our clutches are now, the belt doesn't bottom out on the secondary, just as nyroc says. That is because our belt isn't wide enough to be pushed to the top of the primary and pulling it down into the bottom of the secondary.

To get material that we remove, we took our primary off, measured the distance at the very top, between sheaves when they are fully closed. we took that distance and subtracted the distance between the sheaves where our belt left the mark where it had been running. The difference would be what was removed. To get that distance we had to change the angle at the bottom and it made the belt slip on take off.

I shouldn't even be talking about this, don't do it, you'll end up ruining your clutch! Forget about the milled clutch let's work on a belt or cdi.

We're fairly sure the belt bottomed out on the secondary when we run with the milled primary clutch. We had put chaulk the bottom of the belt and it marked the center of the secondary. If infact it did bottom out on the secondary and didn't get to the top of the primary, then a wider belt alone wouldn't get us all the speed possible to have. That is why I think the belt was designed to short and too narrow on purpose to limit our top speed to around 65 MPH.

I was using a p650 belt.

 

SHOTGUN... the sad thing is, the snowmobile clutches with the idler shaft run though the swing arm pivot, sounded like a great idea... a switch of the sprocket, to fine tune the final ratio... it would be easier to fab a belt cover than machine the primary clutch...WAM

 

Newbeatle;

I hear ya;

I'm on that when I get time!!

Bang--

 

Maybe therock can get something cooking with a wider belt then.....

I blame Alltoys for infecting our minds with delusions of grandeur; and tops speeds we can only dream of doing once before warping into another dimension..... [img]i/expressions/face-icon-small-wink.gif[/img]

AH, but it's fun to think about the "what if" stuff even if nothing comes of it.

 

If you want more top end, turn your belt over.

Bang! [img]i/expressions/face-icon-small-wink.gif[/img]

 

I feel the way nyroc does. If I get 72mph from my P650 I will be happy. I wonder if Bearman had any clutch work done when he got is 75mph? If I recall from our phone conversation all he added was a P360 belt.

I dont mind messing with the springs or buying a new, wider P360 or P700 belt "when the time comes". Experiementing with the weights is to expensive for me. Fooling with the pulley sheaves is totally out of the question.

Mike, you are very fortunate to have an extra set of pulleys to work with and have someone to make your weights.

 

WHOO HOO...Guys I'm pumped...I did some belt shopping today from my suppliers... I found a number of belts varying in 1/8" increments in length & width, from what I feel is a good place to start... the kicker is the cheapest is $45.00, & the most expensive is $81.00 ... I'm going to hold the part numbers until I get a chance to test them, just to make sure, but they are both a little wider & a little longer... I was able to find the exact size I was looking for ( not the stock size, but what I feel we need to go to on width & length to maximize the clutches ) ... so I'm really pumped... I'll do some research to determine which 3-4 sizes I want to test, & get them coming...then I'll be busy next week, but perhaps the next week DIRTYWHITEBOY is off, we could test them ???? 2 of the brands of belt are commercial variable speed belts, & one is a major manufacturer for snowmobiles... can you say 5-10mph more top end, on a $45.00 belt...I can...WAM