Secondary Clutch question

[mwolff]

Hoping to get pointed in the right direction..........
New to sledding this year, very deep background in automotive repair world so I am not a newbie to design, function etc... but I am puzzled.
2007 Venture Lite - 10k
Looking my sled over and while doing so I found the belt sits deep in the secondary clutch. I looked here and it seems some say there is a base adjustment for sheaves but when I took it off I don’t see wth they are speaking of so I think that was another clutch type.
anyway spec says 1.5mm above to .5 below and I am 2.2mm pretty deep......
Belt width is 35mm which actually a bit wider (my spare as well) than what they say new is 34.1 and well above min width 32.5
I saw a post talking about putting shims under the 3 bolts on the backside..... but that doesn't make alot of sense (prove me wrong please) as when I remove the 3 phillips head bolts the sheaves do not move closer together. If adding shims under them would make a correction I would imagine I would see the sheave base setting close up? Wouldn't I?

One reason for looking things over is to get familiar with the sled. Other is that I am finding it is surging when I was going slower like through a bush trail.... Its damn near impossible to keep at a steady slower pace.
Based on my limited experience it felt to me like a clutch coming in and out, maybe? Causing load-low rpm and then picking up again… pulse pulse pulse jerking me around on the sled, get RPMs up and its smooth.
When I had the secondary off I noticed that it was not aligned properly to the primary so I will reset that when reassembly occurs.

 

[Mooseman]

The clutch is adjusted by taking it apart and removing or adding shims between the sheaves. And there's also the question of which belt you have.

Difference between 8GS and 8GK belts (Reverse Update)

Some have asked what the difference is between these two belts. The 8GS was the original belt used with 07 and 08 Venture Lite/MP and Phazers. The 8GK is the updated belt used on 09+ as well as those earlier sleds that were updated with a shim in the secondary. The first pic is with both...

ty4stroke.com

So if you have the 8GK belt, then it's been updated and a shim added. It will sit lower in the sheaves to put less tension on the reverse gear and ease shifting. However, takeoff may be a bit lower, like taking off in 2nd gear.

Normally, the belt would sit at the top of the sheaves with the bottom (lower part) of the ribs sitting even with the sheaves like this.

With the update, the top of the ribs will be even with the sheaves. Yours is way too low.

However, as you've seen, your clutch is different than the others. No bolts, no easy adjustments. You have to take the clutch apart and remove shims from in between the sheaves. To bring the belt higher, you have have to remove a shim(s). Take note that you MUST replace the circlip with a new one and make sure the flat sharp side is pointed out. Use the old one during adjustments with shims and then replace it with the new one on the final time. It's a PITA but too many have failed with reused clips and even with new ones. It's a terrible design. And those 3 screws are only to hold the sheave's bushing so don't remove them.

And make sure the belt is properly resting in the clutch by lifting the rear of the sled and spin the track a bit and letting it stop by itself.

 

[mwolff]

The clutch is adjusted by taking it apart and removing or adding shims between the sheaves. And there's also the question of which belt you have.

Difference between 8GS and 8GK belts (Reverse Update)

Some have asked what the difference is between these two belts. The 8GS was the original belt used with 07 and 08 Venture Lite/MP and Phazers. The 8GK is the updated belt used on 09+ as well as those earlier sleds that were updated with a shim in the secondary. The first pic is with both...

ty4stroke.com

So if you have the 8GK belt, then it's been updated and a shim added. It will sit lower in the sheaves to put less tension on the reverse gear and ease shifting. However, takeoff may be a bit lower, like taking off in 2nd gear.

Normally, the belt would sit at the top of the sheaves with the bottom (lower part) of the ribs sitting even with the sheaves like this.

With the update, the top of the ribs will be even with the sheaves. Yours is way too low.

However, as you've seen, your clutch is different than the others. No bolts, no easy adjustments. You have to take the clutch apart and remove shims from in between the sheaves. To bring the belt higher, you have have to remove a shim(s). Take note that you MUST replace the circlip with a new one and make sure the flat sharp side is pointed out. Use the old one during adjustments with shims and then replace it with the new one on the final time. It's a PITA but too many have failed with reused clips and even with new ones. It's a terrible design. And those 3 screws are only to hold the sheave's bushing so don't remove them.

And make sure the belt is properly resting in the clutch by lifting the rear of the sled and spin the track a bit and letting it stop by itself.

Thank you for the info!

 

[74Nitro]

Update to this thread. The 'surging' issue at lower speeds was the TPS sensor. Replaced with a new one from Yamaha.

 

[mwolff]

Update to this thread. The 'surging' issue at lower speeds was the TPS sensor. Replaced with a new one from Yamaha.

100%
Beuerman Recreational got me fixed up. Got out for the first ride of the season yesterday and no surging at all, so much nicer to roll through a slow speed section without bouncing all over the place.