cutting primary clutch

[pei apex]

I took my apex to dealer for 500 mile service.the mechanic said the belt was not going anywhere near the top of the primary clutch.he took it off and shaved some material off both sheaves and the split collar.he said the belt would go higher now.was this a good thing to do? we lost our snow so I can't try it.I told a buddie about it and he said I would have to cut my secondary for it to have any effect.the sled was working great and I wish He would have left it alone.any feedback would be appreciated.

 

[snowbeast]

No its most likely going to be ok as is,but like your bud stated take your helix off and have .125-.150 taken off the inside of the center of the hub,you can see where the bushing is inserted into the hub,you chuck the helix up on a lathe and remove the amount i stated above from the hub where the bushing is,and it will now match the front sheeve clerance,all you are doing it overdriving you cvt system,i generally do this if it did not come set up for overdrive,you may have to change your primary spring and some weight on your ramps,and or change your secondary spring pos.on the helix tighten it up some,it is at 70 now try 80 because you will lose some rpms..

 

[pei apex]

mnmsnowbeast: thanks for your reply.I believe that a dalton helix does not need to be cut.is that correct?

 

[journeyman]

hmm, this sounds strange. I have never been a fan of over driving the Yammie clutches. How many miles are on the APEX? What rpm's are you seeing. I know they take awhile to break in. I believe 10,400 is the target. I know many have said they are under revving in the mid 9's during break in. The reason Yamaha does not overdrive their clutches is to keep the belts from blowing, hence climbing over the top like Polaris and Doo are known for. It just seems strange a dealer would do this to a brand new sled under warranty. I am sure Yamaha wouldn't be too thrilled with this one.

 

[rlemotorsports]

Heres the deal. Take the primary off and pinch it between centers on a lathe. Take .020 from each flat spot next to the post. Sometimes the split collars protrude from the flat area. Take all measurements from the face not the collars. use carbide. The split collars are hardened.
Sand with 60 grit to ease the edge and increase up to 180 grit. NEXT. If stock helix face .040 from Face next to bushing. If aftermarket do nothing. After market helixes are shorter. This will make a new belt move up the primary to 5 mm (.197") Stock is 10 MM. I have been doing this since 1995 on dozens of sleds. leave gearing stock.

 

[pei apex]

thanks for the info guys

 

[snowbeast]

mnmsnowbeast: thanks for your reply.I believe that a dalton helix does not need to be cut.is that correct?

Most likely dalton,hauch,and many helixs that are cut for dealers to sell as a kit,or part of a kit will be cut on the hub for o/drive but give it a try,but be sure to mark your front clutch and run it thru full shift,like 1/4 mile to see if it shifts any further than before,and if possible do this right at the lake or field the same day under the same conditions,if your test surface is loose snow forget about getting full shift,you may have to run a mile to see any kind of improvements,but i have run my old 03 rx1 with two different types of speed sheeves and the hach is the only one i recommend,now what you have done is what we did for years on poos and cats some w/good luck some without much luck,but the hach speed sheeve i put on my yammi worked sweet!!!

 

[170plus]

gonna give this a try as soon as we get it to the shop friday morning as well as 500 mile check up,back clutch is all done but front needs some trimming up,so far ive seen 122 on speedo beside a 02 xc800 running 118 on his speedo,last year my rx1 would read 132 beside him at 118 on his speedo,06 speedo's closer to real world than 03-05 dreammeters ?