Clutching question

[skibreeze]

I have a stock 07 600 and it seems to rip it up really good in most snow conditions. It usually has a max recall of 85-8600 at the end of the day. It mainly stays in the 81-8200 range.

I replaced the weight bushings as they were shot and also shimmed the primary the other day.

Yesterday I took it out in some of the deepest snow I've ever ridden and it would only pull 7500. It was that way all day in the deep. The kind of deep, that you rarely ever let off the throttle at all.

My question is, could the shimming pull it down at all? I'm thinking not. My buddy is thinking that the initial angle is too steep. He just changed his in his 660 and it was spinning over 8000 all day. Interesting thing is he is running the same 54's as me.

 

[hardhat32]

From what I can gather, the helix angle will start to increase at around 29 MPH with the stock 56/42.36 helix. The angle will get progressively steeper as the secondary shifts back to the starting point.

I'd be interested in how your sled reacts to having the shim in-between the rollers and the snap ring. If that is what you were talking about.

 

[Ron]

Ski-what did you shim? Buttons, spider or weight shims? One thing that would affect R's would be the spider...shimming for belt side clearance. Generally tighter side clearance = more R's unless you used an old belt and went too far.
If you shimmed the buttons and got them too tight that can cause a drop in R's.

 

[skibreeze]

Ski-what did you shim? Buttons, spider or weight shims? One thing that would affect R's would be the spider...shimming for belt side clearance. Generally tighter side clearance = more R's unless you used an old belt and went too far.
If you shimmed the buttons and got them too tight that can cause a drop in R's.

I just shimmed the primary for belt side clearance. I shimmed it to .010 for an unused belt. I am using a used belt, so there is more.

How does shimming the spider affect rpm's?

 

[Ron]

I just shimmed the primary for belt side clearance. I shimmed it to .010 for an unused belt. I am using a used belt, so there is more.

How does shimming the spider affect rpm's?[/QUOTE]

It changes the position that the weight sits on the roller-the starting point. Generally the closer the starting point is to the heel, the higher the R's at initial shift also some effect past initial. This is because the weight has more leverage, the clutch is more efficient at low shift points.
As the belt wears or you run more belt side clearance the weight is farther up the roller and has less leverage, less force, lower R's. It's more noticable on a 600 since they have less torque. Have you ever had someone complain about poor performance only to find that their belt was well worn, put on a new belt and all is well?

 

[skibreeze]

Have you ever had someone complain about poor performance only to find that their belt was well worn, put on a new belt and all is well?

I have definitely heard that. That's why I was surprised by the rpm drop when I shimmed it to the correct tolerance. It ripped pretty darn well before. Now of course the snow was also extremely deep, so I know that some of the change were the conditions.

 

[diamonddave]

Also, run the 64-44 helix.

 

[skibreeze]

Also, run the 64-44 helix.

I need to check what is in it, but a friend just put in a 56-38/56-40. Don't know which one he is running in his. Alot different than what you are recommending.

 

[skibreeze]

Ttt

 

[Boston Racing]

I was running the 64-40 .40 / 62-38 .40 that carls cycle sells for the 660 at first and it would pull the r's down on a long pull at low track speed. I replaced it with a 56-38 .36 and in 4ft of powder WOT all day it never dropped below 8k and most of the time was at 8250. I think the stock 56-42 .36 has too much finish angle for us. Carls swears the sled should pull 58g weights and the 64-40 .40 helix but it just wont at 10k -12k feet. I am happy with it now....until the 860 kit comes

 

[skibreeze]

I looked in the sec. and it still has the stock 56-42 .36 and the red/black spring. I need to possibly get the 56-38 .36 I also might have to get some 52g weights after shimming the primary.

 

[Boston Racing]

Carls rec. a black/purple or black/white in the secondary as well. I have the black/white and have a black /purple here you could try. When mine was still a 600 I ran the 10AL weights which I think are 53's

 

[Ron]

For $20 and I'll send you a new set of 10A's, shipped Priority Mail-they run 63 +/-.

 

[Ron]

For $20 and I'll send you a new set of 10A's, shipped Priority Mail-they run 63 +/-.

Yes-had that wrong, 53. Were your weights hanging on the spider-that would raise R's. If they were you could have flat spots starting to form on the rollers.
Shimming belt side clearance should have helped not hurt R's.

 

[Boston Racing]

I think alot of the rpm loss was due to the bottomless power causing a high load. I think the 38 finish angle is the ticket. Even the 800 guys are going to shallower helixes for the high altitude and powder. Next time we ride Skib we can swap secondarys and see how it acts.

 

[mtnclimber19]

I am running 10-56s in my wifes 600 with a slp pipe and running a 60-38 helix with a black/purple spring at 8-10k and seems to work really well. It will lose a couple hundred rpms on a long climb in deep snow so I am thinking of trying a black/white spring to cure that.

 

[skibreeze]

I think alot of the rpm loss was due to the bottomless power causing a high load. I think the 38 finish angle is the ticket. Even the 800 guys are going to shallower helixes for the high altitude and powder. Next time we ride Skib we can swap secondarys and see how it acts.

That's what I'm hoping. It rips everywhere else, so it was either the nipple deep snow or the shimming affecting it.

 

[CO 2.0]

I bet the snow had a big effect on it. My Dragon ran worse than it ever has down at Wolf Creek this past weekend. 7400-7500rpms tops in the pow.

 

[skibreeze]

I bet the snow had a big effect on it. My Dragon ran worse than it ever has down at Wolf Creek this past weekend. 7400-7500rpms tops in the pow.

I ride with Boston Racing, So I will try the helix that he just got and see how that runs. His was able to keep the rpms all day.

 

[hardhat32]

My dad runs the 10-AL's (53g) for 8,000+ feet. I rode it on the trail one time and it ripped. Once it got over 8,000 RPM it really came to life. It was stock accept an HPS can.

It runs good in the snow, but I'm not sure what RPM it pulls. He doesn't really watch that much.

I always seem to notice a loss of R's in the snow, and I always thought it was air restriction from snow in the intake. However, I was was still noticing it on my 700 last year when the intake was clear and still noticed a loss. I got a 58-40.46/58-38.46 helix and a different spring. I was trying both angles on a hill and didn't notice much difference. There wasn't much run at the hill, and I checked speed one time and I was at around 25 MPH which would put the clutch ratio at about 30%. When the secondary is at .3 the angle on the helix would be around 45 degrees with the 58-38.46, 46 degrees with the 58-40.46, and about 44 with the stock 56-42.36.

I'm planning the try the SLP shim, but I'm starting to think that a .46 helix is not a good thing to run in the 700s and 600s over 8,000 feet in the steep and deep. My gut says to shim a .36 so it is a .30, but I'm not sure if that would be a bit overkill.