- continued

10.30.09:

Question: I have a 2005 sno pro 440 stocker that I'm racing this season and when idling and track lifted off the ground, there are sparks from the brake area. I was wondering what could cause that. Could the brakes be locked up or what? I'm confused. Thanks.

Answer (Russ): While it's not abnormal to have some small amounts of sparking off the brake pad/disc combination when making contact due to the fact that you have a ferrous metal disc and a metallic pad, it sounds like your situation may be a little more complex. I'm assuming your belt deflection must be on the snug side if your track is spinning while idling, but either way, on a high time race sled, I would make sure you don't have a top bearing issue in the chain case or a caliper that needs service and could be hanging up. I would also inspect the condition of the disc itself, check for wear, run out, etc. You might want to be sure when you change the brake fluid that the small compensation port in the master is open and not clogged from contaminated fluid. I've seen poorly installed hand guards not allow the lever to completely return freely and cause similar issues. One more thing, if your pads are worn out and the pistons in the caliper are out quite far, they sometimes can lose their ability to return nicely and could cause some small amount of drag.

10.29.09:

Question: My son will be racing the Junior Classes and we are getting a 2010 Polaris LQ 600. My question is with the throttle restriction will I have to make changes to the stock set up, clutching, gearing, carb?

Answer (Tim): I believe when this concept was discussed and decided upon the goal was to end up with current race 600s that had 440 power and speed. With that in mind, I think I would start with the 2007 440 IQ clutching. The Team secondary on the 600 and the 440 are pretty similar in tuning components and the primary spring is the same so all you would need is the primary weights. You can order the weights through Brad Seavers at the Polaris Race Department. The weight is S-51, the part #1321731 and you will need three of them. I have talked to Brad about this and he will be able to get the weights for you and anyone else that is interested.

10.27.09:

Question: I have a 2010 Polaris and I am a small person. I weigh 130 lbs. What are the stock specs on the shocks and what do you recommend I get done to them? Just a revalve?

Answer (Tim): The stock shock specifications can be found in the 2010 Polaris Race Manual. I recommend to try the sled with the stock springs with the shock clickers turned down to the lowest settings and if it is still too stiff, contact the Polaris Race Department at 715-355-5157. They may be able to help you with updated valve specs or possibly re-valve your shocks for you softer for your weight.

The other option is to go with an aftermarket shock. The nice part about buying a good quality set of aftermarket shocks is once you get them set up for your riding style and weight you can keep transferring them from your old sled to your new sled each year which is what we do. We use Fox Zero X shocks on the rear suspension and Fox Float Evol air adjustable progressive shocks on the front suspension. The Fox shocks that TJ Gulla won the 2009 Pro Open Championship with are 3 years old! If you are interested in Fox shocks, you can call Dean Geery at 831-768-4842.

10.15.09:

Question: I am just getting into snocross and I have a 2008 600 RS. How do I get the racing manual? What are some of the issues Team Ski Doo had with the 2008 600 RS? What should I have on hand for spare parts at the track? [Submitted by Nick, Eau Claire, WI]

Answer (Greg): You can get a race manual if you go to www.shopbrpparts.com. As far as the 2008 600 RS, there were a few things you need to be aware of. Check your exhaust pipe support where it is sprung under the head pipe. Extra springs will help. Also, take off your bottom slipper gear and check the snapring retainer to make sure it is all the way seated. Check the front support plate for loose bolts or rivets and make sure everything is tight. Check coupling bumpers on rear of rails as well as rear of rail where the axle tightner attaches and check the track for broken or missing lugs. The 2009 track is ISR filed to run on that sled. All of these issues were resolved on the 2009 600 RS. Good luck this season.

Question: I'm a second year racer and I am looking into getting a new set of skis on my sled. What's the best set to get that will improve turning and handling and yet still be leagl for racing?

Answer (Tim): We use the C&A Pro XT ski with a 10" Woody's carbide. It is by far the best turning ski and carbide that you can buy. You can find them at www.caproskis.com and www.woodystraction.com.

10.8.09:

Question: Very often I read about the need to clutch for different snow or track conditions. Could you touch on the basics of what needs to be achieved in different conditions?

Answer (Tim): There are as many ideas and theories about snowmobile clutch tuning as there are racers. Here's a quick version as it pertains to snow conditions.

The objective with snowmobile clutching is to keep the engine RPM at peak power anytime you are wide open throttle. With the 2010 Polaris 600 IQ the peak power is achieved @ 8500 RPM.

Lets assume you are satisfied with your clutching for a particular temperature and snow condition and your engine is turning 8500 RPM. As the ambient temperature increases, the wetter, the heavier and the stickier the snow becomes. These things plus the higher carb air temp that results in a power loss, all will contribute to a lower than desired engine RPM. To adjust for the warmer temp and wetter snow and raise your RPM, you can do one of four things: you can either lighten the fly weights in the primary clutch, use a higher rate primary spring, use a higher rate secondary spring or use a lower number helix in the secondary.

Most racers will grind on either the sides or the back side of the three stock style fly weights equally and have a few sets on hand in .5 gram increments for varying conditions or, use an aftermarket adjustable fly weight that you can add or remove weight as needed. The nice part about the aftermarket weights is when you go too light, it's just a matter of adding the weight back in.
When the temperature goes lower, your sleds engine will want to over rev to a higher than desired RPM and you will need to go in the other direction with a heavier primary weight.

9.30.09:

Question: What is the difference between a snowmobile Fox Evol X and an ATV Fox Evol X? Being on a strict race budget, you can find used ATV Fox Evol X's at a fair price, but no snowmobile intent. If the mounts can be changed and the valving has to be modified for the riders weight, would this be an economical way to go? [S. Tarnowski, MI]

Answer (Rick): The evols are the same parts, but the lengths are different; also valving and mounting. This gets to be a lot of work to change out everything and the price will be very high. It is much cheaper to have two sets of shocks.

9.28.09:

Question: I have an 03 Rev 440, rear suspension feels normal until the temperature gets below about 15 degrees. Then it feels like it's frozen (way stiff, then loosens up a little). I had it rebuilt and since then it has been acting that way. [submitted by Jim, Shakopee, MN]

Answer (Rick): It sounds like you have water in the cross shafts or not a good low temp grease across the shafts. Be sure to grease the suspension with a low temperature grease.

Question: How do I know the correct gearing for snocross? Should it change according to track conditions?

Answer (Greg): Our stock OEM gearing for the 600 RS is :23-49, which, if you look in our current race manual, is geared for approximately 85 mph. Rider weight, snow conditions, elevation and track length are generally the determining factors for gearing. On shorter tracks many riders will gear down to 1 to 2 teeth on the top sprocket.

Generally clutching changes should be made to adjust for changing track conditions.

Question: In pre-season testing, what RPM should I be clutching for with the new Sno Pro?

Answer (Russ): First off, are we talking snocross or terrain type racing as pipe heat and the time at full TVO are factors here. My recommendation would be leave the clutching stock for the pre-season testing! If we find a clutch package that enhances snocross performance, it will be available from Speedwerx. Depending on density altitude and pipe heat, you could expect to see 8400 RMP on short pulls if you use the preheat button and slightly less than 500C on your data logging system. A long hard lake pull with 600C pipe temp may yield 8650 or even slightly more depending upon conditions.

9.25.09:

Question: If I'm bottoming out, how can I tell if I need stiffer springs or stiffer shock valving?

Answer (Rick): If you have a compression adjuster, first try stiffening it up on the rear shock. If the rear spring has adjustment, you should first adjust the cam adjuster to the stiffer setting. If both of these don't help, you should try a stiffer spring on the rear.

Question: How can I make my sled turn better?

Answer (Andre): Try pulling your limiter strap in by 1 hole. This will increase ski pressure. If this doesn't solve the problem, try using a 1" keel aggressive ski, for example, C&A pro. This will help solve the problem.

Question: What fuel should I run in my stocker? Race fuel? If so, what octane? Or should I use 92 pump gas?

Answer (Tim): We use a 50/50 mix of Polaris 110 race fuel mixed with 87 octane pump gas with ethanol. We pick one gas station to get the pump gas from and stick with it for the season.