I don't quite have the helix thing down yet. I have a 98 xc700 and have a polaris r-32 which is a 50-34 that I think explains my slight over-rev even with 10-62 weights. If I go to a 36 degree on thop top it should bring down my rpm. It seems most people with this sled are running a polaris r-11 which I think is a 44-36. If I go to this helix will I notice a big difference besides top end rpm? will it be noticeable out of the whole and in the midrange? What do you guys think?
You can also use a R-12 which is a 50-36 helix. This is what i use along with a silver/blue secondary spring and Dark blue/white primary with 10-62 weights. This setup runs just under 8000 rpm on my sled.
Run the 50/34 with 10-64 weights you will have better backshift with the 50/34when you hit the corners than you will have with the 50/36.Never use your secondary clutch to control top end rpms always use the primary or you will lose your clutching efiecency and run into belt slipage,which is lost power to the track.
With the 10-62's you should be ok. The over rev is ok too, as long as it is only for a second or two. Then it should hang on at 8,000.. With the steeper angle helix your sled should shift down rather quickly. If it isn't then I'ld move your sec. spring down one hole or check it out you may have too stiff a spring in your secondary and it is holding up the shift. Do you have the stock silver spring in there or what?
If your sled is always over the limit I would recommend that you try heavier weights first. Tune your RPMs with the primary, weights and springs, then do the rest. If the revs come down yes then it is the secondary you play with.
Skidplate, It's not over by much, but I have been told by several people that I should keep the final angle at 36 degrees because this is what the stock helix was. Is this true? Can you tell me if a 44/36 or a 50/36 is better and in what area? Thanks.
Yes, stay with the 36. You don't need alot of side pressure at full out anyhow. As for the 44 or the 50 the 50 will really pull hard out of the hole. (upshift) you may notice that it doesn't backshift as quickly as the 44. You will notice this on trails and deep snow. You have a motor that really likes to pull so if you can why not try the 50 first and see how you like it. If you don't then you have gone to far. This could get rid of the over rev you were talking about cause the 50 will make you motor work alot harder. It all really depends on how you ride and how "intune" you are with your sled. I have friends with 700's and they are using some serious weights and big helixes with amazing results. They just play around changing everything constantly they kick some butt but I'ld rather spend my time findng the fields with no tracks,YET!
It is awsome on the trails with the 50/34 that I have in there right now. The back shift is great and it upshifts hard. I will try a helix with a 36 degree final to bring the rpm down a little on the top end. Or maybe I should try some 10-64's in the primary? To many choices!
i got a clutch kit from cudney racing just talk to them they will set you up i have a 2000 xc sp 700 and they fixed me up with a great kit i think the helix is a 48-36 it turns up to 7900 and works great cudneyracing.com
Always remember to do one thing at a time. Factory helix angles are pretty good. Weighting down the clutch on the 700s and 800s is the first step.
After you find a weight that fits you, try higher engaging drive springs. Always record your results after EACH single change.
I would only start on the helix after I obtained a kick-ass drive setup. Remember that the helix is nothing more than a gear box made out of ramps. Usually, getting the drive nailed down and studding the track makes for a great ride without touching the driven helix.
Also, tighten up the drive belt until is just barely "squeaks" at idle...just barely.
Gates Belt company has some really good literature on thier website regarding CVT clutches. Everyone should check it out.
A forum community dedicated to snowmobile owners and enthusiasts. Come join the discussion about performance, troubleshooting, trails, maintenance, riding tips, modifications, classifieds, accessories, and more!