I am replying to two letters that were featured in the October/November 97 issue of SnowTech. While you had some good points, I feel that you left out some critical information in your responses.
First, in regards to Kyle Ohnstad’s questions about the ’93 750 Storm- Wiseco does not offer pistons or piston kits for this motor. Only Polaris offers pistons for the 750 motor in std, .010, & .020 over sizes, and unfortunately for riders these are quite expensive.
Second, the 750 and 800 motors are quite a bit different, especially from year to year. The 800 cylinders will NOT directly bolt on the 750 cases. The cylinder sleeves and piston skirts need to be machined to make the fit work. Also the 1994 Storm received factory updated pistons (same as the stock 1995 pistons). But the 1995 Storm received factory updated cylinders and pistons (which basically made it a 1996 motor). The 1996, 1997, and 1998 are the same Nicasil cylinders and C series pistons.
Third, the best cure for any Storm is a big bore kit. The cases are quite large and accept big bore kits very well. Both PSI and Legend Performance have quality kits that work wonders on these sleds (especially the ’93-’95 models). In my professional opinion, Kyle would be better off with one of these big bore kits or getting a new sled.
In regards to the knife edging, if the cylinders are properly size and chamfered and the updated cooling system is in place you should not have a problem with knife edging. We have several Storms in use with over 7000 trouble free miles on them! Although much maligned, the Storm when properly set up and maintained is a powerful, reliable, and fun machine.
Next, in regards to the troubled XCR600SP’s- there is a cure for the stumbling blues. We have spent many many many hours dialing these sleds in, and having run them for the past two seasons are quite familiar with them. First of all the stock clutching was way off. We have assembled a good clutching kit from Polaris parts and Goodwin Performance has an excellent kit as well. Second, regearing does help. I suggest 1 tooth smaller on top. Third is carburetion, they can be leaned out but be very careful here as they will burn down easily! But for 0-3000 ft at -20 to +10 we run Mag 370, Ctr 370, Pto 350, Pilot 35, and needle in #4. We also recommend drilling out the pilot hole to .047″ and running the 3.0 slides (but the slide change is not absolutely neccessary). Fourth, the pipes are flat out wrong on this sled. They are the EXACT same pipes as on the Storm and Ultra SPX, and basic two stroke knowledge tells you that this won’t work. I definitely recommend different pipes or at the least a new muffler from Dyno-Port. It is truly amazing how much this helps. Fifth, I suggest a set of Carbon Tech reeds. The throttle response with the reeds and muffler is tremendous and needs to be heard to believe! Sixth is to roll the timing BACK a bit, yes I said roll it back. Seven, adjust the RRSS block to the back hole like the ’97 has. This gives a much better holeshot and weight transfer. Last, if you have money to spend, install the 1997 CDI box as it has a different ignition curve and helps prolong piston life under racing conditions. Making all these changes adds up to a completely different sled from stock and makes it very fun to own and ride, not to mention VERY fast!
Keep up the good work, I do enjoy your magazine quite a bit.
General Manager – F&R Sales & Service
Polaris Master Certified Mechanic & Dealer
Thank you for sharing this excellent information with us John.