I wen't out racing today it was 0 to to +1 (whatever temp Canada uses), I ran 107 MPH in 2000 feet but the rpm only came up to 7800 could this be because the sled is jetted for cold weather, about -10.
I agree. We need to know what rpm it's supposed to be at. You shouldn't have to shave the helix just to change your rpm a bit. But, if you still want to change it, then buy a second one with a different angle, this way you'll have 2 helix's to choose from.
The first thing i would do is make sure both your clutches are clean and nothing is worn, binding or broken. Make sure your belt is still good. Then if you still need to raise your rpm a little, you can tighten up the spring on the secondary clutch which will raise your rpm 100 or 200. This is the easiest way for fine tuning. To do this on a AC, you just remove the clutch tower and move your spring into the next tightest hole, usually up one number.
If your rpm are still too low than there are many many other possible causes, but i would not change your helix to fix your problem.
By changing the helix, your not just changing your rpm, it's changing the entire clutching setup: from WOT rpm, to backshifting, upshifting, holeshot, speed, ...just about everything! You should select a helix based on your riding style. Everything else can be adjusted accordingly.
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