Best high altitude clutch for M7

[M_builder]

Bought a 2006 M7 and was wondering what would be the best clutch for high altitude riding?

 

[M_builder]

Anyone?

 

[motoxxman]

If you are going for a lower cost do it yourself type clutching upgrade, for my 07 m8, for high altitude (9k + ) i did the 68gr weights, gold spring in primary (p/n 0646-376) and the bdx shift assist washer. The spring lets it engage at much lower rpm's so for the older sleds like yours that like to trench, it helped me out a ton! The lighter weights will give it more throttle response. Its no full clutch kit, but for an older sled it will give it a nice feel.

good luck....

 

[CATSLEDMAN1]

If you have stock gearing, I never found a really good hi altitude clutch setup, just lots of almost . Once geared correctly, lots of clutching issues just go away.

 

[M_builder]

If you are going for a lower cost do it yourself type clutching upgrade, for my 07 m8, for high altitude (9k + ) i did the 68gr weights, gold spring in primary (p/n 0646-376) and the bdx shift assist washer. The spring lets it engage at much lower rpm's so for the older sleds like yours that like to trench, it helped me out a ton! The lighter weights will give it more throttle response. Its no full clutch kit, but for an older sled it will give it a nice feel.

good luck....

Thanks for the advice, I'm going to order the bdx shift assist washer and the 68 gram weights. If that doesent work I'll try different primary springs

 

[boondocker97]

A M7 is not going to pull the same weights as a M8 without a stiffer primary spring. 68g will be too heavy at 9000'. I run the stock yellow/white primary spring, I think 64.5g weights (would need to look and confirm), RK Tek torsional secondary with snopro green spring and 36/34 helix. Unfortunately RK Tek doesn't make these anymore. I'm running 10.4 diameter secondary as well as it helps the takeoff and bottom end without dropping motor engagement too low. I tried gearing down to 53/67 but it was a little too low. 55/65 would probably be good. Sled turns a 162 camoplast 2.5 track with single pipe and head.

 

[M_builder]

A M7 is not going to pull the same weights as a M8 without a stiffer primary spring. 68g will be too heavy at 9000'. I run the stock yellow/white primary spring, I think 64.5g weights (would need to look and confirm), RK Tek torsional secondary with snopro green spring and 36/34 helix. Unfortunately RK Tek doesn't make these anymore. I'm running 10.4 diameter secondary as well as it helps the takeoff and bottom end without dropping motor engagement too low. I tried gearing down to 53/67 but it was a little too low. 55/65 would probably be good. Sled turns a 162 camoplast 2.5 track with single pipe and head.

My neighbor has been riding arctic cats for 40+ years, So I think I'm going to try out some different weight weights and stiffer/softer springs while I'm over there today doing some work.

 

[snoxracer40w]

Piggy-backing here. Any of you replace your older M primaries w the newer 746-435 primary? I have one and ordered the bushing kit that the microfiche says is compatible and the bushings are too long for the cam arm bore. Anybody have any other suppliers I should look into, or just cut the bushings to fit?