Yamaha, there is a possibility of someone getting hurt with these SW primaries!

[Thunder Products]

Thought the primary rollers were updated and the 20’s and 21’s were cured.

The only change Yamaha did was like Mike said, added a little tip weight, helix and spring change to certain models after 2017.

The secondary rollers did change from 2017. The secondary rollers flat-spotted immediately so they had to change them.

This pic is the newer style, it has the little 6 divots on each side of the rollers. The 2017 rollers do not have the divots

 

[SideHogger]

The only change Yamaha did was like Mike said, added a little tip weight, helix and spring change to certain models after 2017.

The secondary rollers did change from 2017. The secondary rollers flat-spotted immediately so they had to change them.

This pic is the newer style, it has the little 6 divots on each side of the rollers. The 2017 rollers do not have the divots

View attachment 158706

Any problems with the new ones? Do they last?

 

[Thunder Products]

Any problems with the new ones? Do they last?

No, they are flat-spotting also.....but not as soon.

The dimensions are not good either....way too sloppy for my taste

 

[jonlafon1]

QUOTE FROM thunder products

"So this is where the other percentage of these clutches are letting go is because of the cracking through the allen screw holes that hold the weight pin...which for years I have been posting pics of and now catching more of these through dye penetrant testing"

Is this from over torque on the set screw? OR the harmonics on the pin that then travels into the set screw and > thin material around the set screw. Every time I put that set screw in I try not to over tighten it.. Then my mind travels to the thinner material on each side on that set screw.. I'm not so sure I care for the set screws for weights or pins on sleds known for harmonics.. Or in general

 

[Thunder Products]

QUOTE FROM thunder products

"So this is where the other percentage of these clutches are letting go is because of the cracking through the allen screw holes that hold the weight pin...which for years I have been posting pics of and now catching more of these through dye penetrant testing"

Is this from over torque on the set screw? OR the harmonics on the pin that then travels into the set screw and > thin material around the set screw. Every time I put that set screw in I try not to over tighten it.. Then my mind travels to the thinner material on each side on that set screw.. I'm not so sure I care for the set screws for weights or pins on sleds known for harmonics.. Or in general

I believe if the hole wasn't there....this might have been a good clutch.
But yes, I can see over tightening that screw and it putting more stress in that area.

 

[jonlafon1]

I believe if the hole wasn't there....this might have been a good clutch.
But yes, I can see over tightening that screw and it putting more stress in that area.

OR how about some more meat around that set screw! At the very least

 

[yamahahaapex]

No, they are flat-spotting also.....but not as soon.

The dimensions are not good either....way too sloppy for my taste

I just ordered a set of primary and secondary rollers as well as a holeshot helix from you last night to ship to Canada.

One of the rollers were not making contact with the ramp and its time its dealt with. Excited to try out the 33/35 helix

 

[jonlafon1]

I just ordered a set of primary and secondary rollers as well as a holeshot helix from you last night to ship to Canada.

One of the rollers were not making contact with the ramp and its time its dealt with. Excited to try out the 33/35 helix

Don't loose sleep about the roller not touching helix.. It will be touching when that clutch is engaged.. I had a new spring I put into secondary this year and only had 1 roller touching.. I just checked this yesterday after 150 miles this year with a new secondary spring and all three rollers are now touching.. Keep your belt even or just below the top of the secondary sheaves.. You don't want the belt riding any higher then that in the secondary..

 

[ROCKERDAN]

I put a power block clutch in this fall.A good friend of mine that I have been riding with for very long time has 12,000 miles on a turbo Viper with the power block clutch . it’s been flawless the whole time

Have you got many miles on the new PB80? I have been thinking that this is by far the best cost alternative setup. Such a simple design, no moving parts(ramps/rollers/bushings ect) so it should be ultra quiet.

Got any pics of it?

I'd like to see the dual spring setup.

thanks
Dan

 

[Snowaddict]

Don't loose sleep about the roller not touching helix.. It will be touching when that clutch is engaged.. I had a new spring I put into secondary this year and only had 1 roller touching.. I just checked this yesterday after 150 miles this year with a new secondary spring and all three rollers are now touching.. Keep your belt even or just below the top of the secondary sheaves.. You don't want the belt riding any higher then that in the secondary..

I noticed a noise while sitting at an intersection with the engine running last weekend. The only time it would do it was while stopped. I didn't think it was a belt squeal, but maybe it was. I checked my belt deflection at home and it was sitting a tad below the sheaves. I thought it was supposed to be a tad above the sheaves? So, I turned my BOP adjuster to raise it. I couldn't really get it to sit above the sheaves, but I noticed the track began to spin faster on it's own (no throttle.) The noise also reproduced itself then. So, I backed off my adjustment and went the other way (which would have opened the sheaves more to drop it down.) The track still "crept" somewhat, but the noise wasn't there. I left it there then. After reading your post, maybe I was wrong with deflection and I should have the top of the belt below the sheaves a slight amount then?

 

[fourload]

I noticed a noise while sitting at an intersection with the engine running last weekend. The only time it would do it was while stopped. I didn't think it was a belt squeal, but maybe it was. I checked my belt deflection at home and it was sitting a tad below the sheaves. I thought it was supposed to be a tad above the sheaves? So, I turned my BOP adjuster to raise it. I couldn't really get it to sit above the sheaves, but I noticed the track began to spin faster on it's own (no throttle.) The noise also reproduced itself then. So, I backed off my adjustment and went the other way (which would have opened the sheaves more to drop it down.) The track still "crept" somewhat, but the noise wasn't there. I left it there then. After reading your post, maybe I was wrong with deflection and I should have the top of the belt below the sheaves a slight amount then?

They usually sit a spec below the sheave. The best way to adjust is to jack the back and adjust until the track starts to spin slightly then back off a little. This will let your reverse work good also.

 

[fatchance]

Correct, just make sure you run it over ground and not just on the stand!

 

[Preacher]

Have you got many miles on the new PB80? I have been thinking that this is by far the best cost alternative setup. Such a simple design, no moving parts(ramps/rollers/bushings ect) so it should be ultra quiet.

Got any pics of it?

I'd like to see the dual spring setup.

thanks
Dan[/QUOTE. I brought my sled up to Fort Kent and we have not had any rideable snow but this storm is just what the doctor ordered so I will be picking up my sled Thursday I’m gonna ride for four days .I will get some pictures for sure

 

[Preacher]

Have you got many miles on the new PB80? I have been thinking that this is by far the best cost alternative setup. Such a simple design, no moving parts(ramps/rollers/bushings ect) so it should be ultra quiet.

Got any pics of it?

I'd like to see the dual spring setup.

thanks
Dan

I don’t have any miles on it yet I brought my sled up in October and put the power block clutch on but I haven’t had a chance to ride it .we haven’t had any rideable snow until this storm.Hey man it’s good to hear from you I hope everything is good for you

 

[jonlafon1]

I noticed a noise while sitting at an intersection with the engine running last weekend. The only time it would do it was while stopped. I didn't think it was a belt squeal, but maybe it was. I checked my belt deflection at home and it was sitting a tad below the sheaves. I thought it was supposed to be a tad above the sheaves? So, I turned my BOP adjuster to raise it. I couldn't really get it to sit above the sheaves, but I noticed the track began to spin faster on it's own (no throttle.) The noise also reproduced itself then. So, I backed off my adjustment and went the other way (which would have opened the sheaves more to drop it down.) The track still "crept" somewhat, but the noise wasn't there. I left it there then. After reading your post, maybe I was wrong with deflection and I should have the top of the belt below the sheaves a slight amount then?

Just below the secondary sheaves is fine. I run mine below all the time. I find the rollers actually make MORE contact when running belt below sheaves just slightly. Not that it matters with the rollers as you engage clutch the rollers will all make contact with helix. Just something I noticed about belt deflection in the last 10500 miles.