Since we’re talking about transfer on mountain sleds, we might as well talk about the new Ski-Doo Summit XP models as well. We found, after riding a number of the Summit XPs, that the amount of transfer was inconsistent. This sled seems to be very sensitive to the limiter strap setting, and in most cases it was simply a matter of letting the limiter out just slightly to remove some of the ski pressure and get it to pop up out of the snow better. But, don’t over do it, this was a touchy adjustment compared to other sleds or what you might be used to. The Summit XP will tend to wheelie really good (or bad) if you let out the limiter too far.
We also found the Summit XP could suffocate in the really deep snow, so anything you can do to let it breathe more is a good step to take. Additional intake vent kits are a good move to keep the big twin breathing in the powder.
And be sure to upgrade to the shorter and wider drive belt that won’t get as hot and should last longer, part number
#417 300 377.

• Arctic Cat M-Series owners can really benefit from a 2 to 3 inch riser block (except for the new 2009 models with the vertical adjusting column). We run into riders all the time that have stock height bars on their Cats and wonder why they are having a hard time maneuvering them properly. If the bars are too low, you don’t have the leverage that you need to throw the sled like you should be able to. The stock M-Chassis bars are maybe the right height for a rider that is about 5’6” tall or shorter.
• Move the front arm’s upper mounting location in the tunnel (of the rear suspension) down to the lower hole position (leave the rear mount location in the upper position). A pilot hole is there on the inside of the tunnel in the frame-doubler plate that you will have to drill out. This really helps with the heavier 1000s that have the added nose weight, but also helps the 800s pop their nose up out of the snow as well. Let the limiter strap out some also helps in this regard.
• The 07-08 M-Series Arctic Cats don’t transfer very well. The result is that in deep snow they don’t get the skis up on top of the snow and tend to trench more than they should. On 2008 models you can help this out by reducing the pressure in the rear rail shock to between 85 and 100 psi, or better yet send your rear arm shock to Andy Youngstrom Gas Shock Repair in Menan, Idaho (www.GasShockRepair.com or 208-754-4373) and have them do their magic internal shock mods that are really the Cat’s meow. They’ve found some mods that they perform that are sure to impress mountain riders.
• On 2007 M-Series models, you can re-valve the rear rail shock to soften the compression dampening (send to Gas Shock Repair) and move the rear arm mounting location forward one inch on the rail.  The crossshaft will have to be eliminated when this is done, but it will transfer much better. By doing these mods, these sleds work much better in deep snow conditions.  They are also easier to handle because they will roll up to side-hill with less effort.

Owners of the Polaris IQ models would be wise to check the camber on their sleds. Many dealers and savvy riders report having to adjust this on their new sleds each year.  If you or your dealer fails to verify or adjust this, the handling of the sled will suffer.
It only takes a few minutes to check and should be done on each new sled.  Also, it is a good idea to check it once a year because if you hit something (even a frozen chunk of ice or snow) could change this.

All of us need to periodically check the adjustment/calibration of the oil pump on your sled. This is primarily due to the extremely sensitive nature of the pump calibration, as only millimeters make a huge difference in the amount of oil delivered. The pump calibration changes slowly over time due to the stretching of the braided steel cable on a cable-driven oil pump.
Generally, most every two-stroke sled (except the E-TEC Ski-Doo) should be (roughly) using about a quart of injection oil to 10 gallons of fuel (one quart per 10 gallons figures out to a 40:1 ratio). Stock sleds are less critical, and those with power-mods are more critical. Therefore, if you are not putting a quart of oil in each time you fill your sled up with fuel, you should be checking your oil pump setting.
On some of the new models the pump calibration or cable adjuster is more difficult to get at, but this is not an excuse not to adjust it. A number of the Polaris 600, 700 & 800 CFI sleds are set really lean and are using less oil than they really should be, so pay attention. When checked, the oil pump was often out of adjustment. It stands to reason this would result in premature wear on the engine.

As many of you discovered last season, the snow was deep out west last year.  Every ride we went on seemed to have 2 feet or more of fresh, light powder snow. It was great riding, but it really worked the sleds hard. Air intakes would plug, underhood heat would skyrocket, and the exhaust would try to cap off. This would all lead to the sled falling on its face (losing rpm) and not going as far as it was really capable of.

1. Adding as much intake surface area as possible. High Flow intakes really helped out here.
2. Venting the chassis for more cold air entrance and hot air escape.  A lot of new manufactures sprung up last year all doing similar kits.  We have found this really helps especially in these deep snow conditions.
3. Sealing the exhaust system at all of the joints and most importantly from the silencer outlet to the bellypan with Ultra-Black silicone. We have found that Ultra-Black works best for this.  It seems like we tell you about this every year, but deep snow riders who fail to seal their exhaust system up will be drawing this exhaust into the airbox, especially when the intake starts to plug.  In turn, the sled will fall flat on its face because there is no oxygen in the exhausted air.  The number of mountain riders who fail to perform this step each season is huge.

Since gas prices are becoming more of an issue, we should cover some of the ways to improve the fuel economy of most any and every snowmobile.
For starters, slow down. The amount of fuel it takes to propel a sled at higher speeds is not linear, it is exponential. The biggest break point on a two-stroke is knowing at what RPM the powervalves (if so equipped) open and close. Operating the sled in the “low port” mode with the powervalves closed is going to provide huge gains in fuel economy (this is one main reason why the Ski-Doo 800R and now the 600 H.O. E-TEC models fitted with the eRAVE system get such good fuel economy as they have a three-position valve program, helping them to get better fuel economy than many four-stroke models.)
Another good practice is to use your brakes less, as using the brakes turns your momentum into heat. Instead, anticipate and let off the throttle slowly and coast to your desired stopping point instead, which is even better than using the engine braking through downshifting clutches (both methods are better than grabbing a handful of the brake lever).
Keeping your sled on a packed path instead of breaking trail is yet another proven method of saving fuel. This is pretty basic, but your sled won’t have to work so hard to get through the snow. Hardpacked trails always let you get far better range than fresh snow, or wet snow. When the snow gets wet, it increases the rolling resistance and amount of energy needed to maintain your speed.
Usually, a lower windshield is going to give you a higher top speed and reduce the wind resistance, leading to better fuel economy. Not always. Consider this one carefully, but anything that reduces your sled’s wind resistance is going to help. Sleds lower to the ground with less suspension travel are generally going to have less wind resistance than tall sleds that catch a lot more air.
With single-ply tracks coming into favor, a lighter track is going to also help your fuel equation. And, a track with lower lugs is going to not catch as much air, but it’s also not going to catch as much snow. Balance the track lug height with the need for traction for where and how your ride.
Another thing to consider is (most often) adding performance parts actually boosts fuel economy. The reason this is true is because the sled typically becomes more efficient than it was in stock form. Therefore, you are typically using a lower throttle position when cruising. Also, the sled is typically tuned closer to optimum and this will add fuel economy.
Another spin off of this would be making sure your clutches are in good condition. Worn out clutch components can cause the clutch to bind and the engine will eat more fuel transferring the power to the ground.  This is true for the rest of the chassis as well.  Make sure the drive chain is tensioned properly, and not too tight. Most obvious is to run the track as loose as safely possible without ratcheting or derailing. A tight track just sucks power and fuel, so anything you can do to reduce rolling resistance is going to help your fuel economy.

We’ve found that fine powder snow can often get into the airbox through the headlight adjuster on the Polaris IQ chassis models, especially the RMK models in the deep snow that was so common in the West this past season. We have had some questions regarding this, and have seen the problem ourselves. The Polaris gurus at Starting Line Products have put together a pre-filter that fastens to the hood in this area with Velcro so that you can still get to it and adjust the headlight, if need be.
A dealer out of Colorado indicated they had a couple of customers who would trailer their sleds (2005 RMK 900s) on open trailers without covers that got so much road salt and sand in their air boxes that it got into the motor and damaged it (remember, the 2005 RMK 900 didn’t have a headlight seal to start with). Therefore, it might be good that if you are going to trailer your sleds on an open trailer to make sure and cover them to eliminate any chance of road grime getting into places it should not be and damaging parts. This may seem logical to most of us, but we still see a lot of people trailering sleds without covers. I don’t know about you, but it really makes us sick to see a new sled covered with road grime or mud on the snow or trailer.

Ethanol fuels are becoming more commonplace throughout the snowbelt. Speed shops and engine builders have traditionally recommended shying away from ethanol fuel whenever possible, because non-ethanol fuel is typically more stable and consistent. However, in some areas you can no longer get fuel without ethanol in it. In other areas, stations that have not sold ethanol fuels are now converting. Those with highly tuned sleds need to be aware that fuels containing 10% ethanol will require different calibrations than fuels without ethanol to maintain a proper fuel-air ratio, especially with highly-tuned engine calibrations.
On carbureted models, it is typically recommend to increase the main jet size 2 to 3 sizes when running ethanol fuels. Fuel injected sleds require different calibrations as well. Arctic Cat has used an ethanol jumper wire on the ECU in the past. Other manufacturers have dealt with it differently.
The main thing is you need to know what kind of fuel you’re using. If you are jetted or calibrated for non-ethanol fuel, a tank of ethanol fuel could be disastrous for the high-performance engine. Check with their dealer or performance shop for the recommendations for their specific model.

The new Polaris belt part number 3211115 found on most of the new high performance models provides extreme durability and lasts extremely well. In fact, it will typically wear out prior to losing cogs or blowing. That is good for most of us, but we have seen this extended durability lead to tuning issues because of the belt wearing instead of blowing. This drive belt will wear narrower and narrower, and as it does, performance will be lost a little at a time.
It will reach a point where the operating RPM will start falling off on long pulls, and tuners will check almost everything else but the drive belt itself.  The drive belt should always be the first thing you check when troubleshooting performance and operating RPM issues. The first question for those asking about consistency problems is, “How many miles does your belt have on it?” Usually, these riders have not changed their belt recently. They think the problem must be something else because the belt is still in one piece and visually looks okay. Just because it is in one piece with all of the cogs still there, it doesn’t mean it is still good from a performance standpoint.

The torque specification for the exhaust probe in the Polaris Service manual part number 9921044 on page 4.25 shows 32 ft.lbs. The tuners at Starting Line Products felt this torque spec was too high and have been telling their customers to use 12-15 ft.lbs. instead.
If you ever pull the probe out of the pipe, you need to apply anti-seize to the threads when it goes back in, and make sure to tighten it only to 12-15 ft.lbs. If you do not use anti-seize or over-torque the exhaust probe, you can easily damage the probe.  Also make sure to zip tie the wire back down just like the factory does. This tip applies to all Polaris CFI models as well as Arctic Cat 800 and 1000cc engines.