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One of the sensors used by the Ski-Doo E-TEC direct fuel injection system is an atmospheric pressure sensor, or air pressure sensor. The air pressure is used by the ECM computer module to calculate the proper amount for fuel needed for the conditions (in addition to many other sensors).

The air pressure sensor on an E-TEC is built into the ECM module, and an air hose runs from the ECM to the air box. The sensor is calibrated to detect the pressure of the air box, so if this hose is disconnected, kinked or obstructed the proper air pressure will not be detected and the machine can exhibit poor performance and/or poor fuel economy. On any E-TEC machine that is not running properly, this air hose should be inspected for proper routing to ensure there are no obstructions or kinks in the hose, and that it is connected. This applies to all 600 and 800 E-TEC engine packages, all models.

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Clean belts and clean clutch sheaves allow the sheaves to better grab the belt with less slipping, that’s less friction and heat. Logically we want to keep the drive belt and clutches free of oil, or any residuals that promote slippage instead of traction.

One question that often comes in is on cleaning drive belts. We’ve always followed the logic of no chemicals, using only a ScotchBrite pad in hot, soapy water. Soap? Something like Simple Green works well. You can scrub the belt clean, roughen up the glazing, get rid of the mold release (on new belts) and make them as good as possible. Do it to the sheaves as well, if needed, to clean away any petroleum or rubber residues that would take away from efficient power transfer. This is also a good time to closely inspect the belt for cord separation, layer separation, or any deformities in the power-transferring surfaces that are not supposed to be there.

Some guys swear by certain cleaning solvents, but we’ve always been of the following of not getting the petroleum-based chemicals into the drive belt and clutch sheaves. You should be able to remove any residues with a scouring pad and a good water-based soap cleaner and keep the system clean.

Some owners of Ski-Doo sleds with the new 800R E-TEC engine package complained about engine misfiring. It is very important for owners of the 800R E-TEC engine package to understand the proper operating RPM of this engine package is 7900-8000, not 8150 RPM like on the PowerTEK version of the 800R.

That means you need to make sure your 800R E-TEC is not revving above 8000 RPM. If it does, the engine management system will engage and the engine will misfire and hesitate. Typically, if you see the tachometer going above 8000 RPM all you need to do is lower the setting of the clickers on the TRA primary clutch.

It is important to understand that the 800R E-TEC will not rev much over 8000 RPM, no matter how high you turn the clickers. To adjust for maximum performance, start at a low clicker position, note the RPM and work up to 7900 RPM, but keep it below 8000. Always start on a low number causing the engine to run below its peak, then work up to the target RPM.

Regardless of whether the 800R is an MX Z, Renegade or Summit model, you have to be sure to have the clutches calibrated for the proper elevation. This engine will not allow itself to rev above 8000 RPM, and is the main cause of misfiring and hesitation complaints from users in the field. If you should experience any hesitation at ANY altitude, it is important to check for proper clutch calibration or adjust the TRA to keep the engine operating below 8000 RPM. On Summit 800R E-TEC models used at elevations lower than 4000 feet, you MUST install a 100-260 TRA drive clutch spring to keep the engine RPMs down below 8000 as the engine makes more power at lower elevations. The part number for this spring is 414 742 200.

One trick that has become more popular is filling the ends of the handlebars with something like an aerosol foam (expanding foam insulation in a can) or some type of silicone (like a tube of silicone caulking). This serves several purposes – it acts as a vibration damper to reduce handlebar tingling, and it acts as an insulator to keep handlebar heater output focused on the metal bars instead of the cold airspace sucking the heat away from the bars.

One company actually has developed a special damping gel just for this application. Called Bar Buzz Kill (what a name) it comes in a tube that fits right into your caulking gun. The custom-designed gel formula greatly reduces the amount of handlebar vibration, and users report being able to run the heaters lower than they used to. This can be used on all sorts of rides; ATVs, dirt bikes, street bikes, sleds, all of it. Check it out at
FrankInd.com on the web.

We came across a really handy cross reference chart for Ski-Doo drive belts that is sure to come in handy for many of you. It pretty much lists the availability and service description of each belt, and what the older belt numbers have been replaced with newer, higher quality applications. Not only what fits, but the compound as well.  Saaweet!  Here it is:

Skidoo drive belt chart

Owners of affected 2009 Arctic Cat Crossfire and M-Series models have been notified of a potential issue with the tightening of the mounting nut securing the fuel pump to the gas tank. Some units have been found to not have adequate tension on this mounting nut.
Arctic Cat has instructed their dealers to tighten these mounting nuts to 20 foot-pounds, which usually amounts to tightening the nut by a half turn.
Units affected include the 2009 M-Series and Crossfire 500/600/800/1000 models in the VIN range of 103896 through 118441. If you have a sled in your possession that falls within this range and the nut tension has not been checked or verified, you should not use the unit until this service has been performed. Contact your local Arctic Cat dealer for further details or to schedule the service.

Riders who are familiar with the traditional torsion springs found in most rear suspensions are often thrown for a loop when it comes to setting the rear preload on a Yamaha fitted with the Monoshock rear suspension. Instead of torsion springs, the Monoshock suspension has a single coil spring on the single shock absorber.
Most of the sleds fitted with a version of the Monoshock suspension are set from the factory for a fairly light rider, under 200 pounds. In our experience the single coil spring does not have the range of adjustability of traditional torsion spring suspensions, meaning that you might not be able to get the proper ride height and preload setting for your weight by simply making adjustments; you might find the need to install an optional heavier coil spring.
How do you check for proper preload on a Monoshock suspension? Yamaha uses what is called a spring sag adjustment, much like what a dirt bike does. Here’s how;

1.    Hang or tip up the rear of the sled so the rear suspension is completely unloaded, that is with no weight on any part of the track.

7.    If required, heavier riders might require the installation of an optional heavier spring.
Generally, you will want to also increase the compression damping along with a spring preload increase. Also realize that as you increase the rear spring preload there will be a tendency to cause the steering to become heavier. If you installed meaty carbide runners to get the thing to corner better, you might find it all to come back into balance once you get the preload set properly. Always verify proper preload settings before making changes to the front end to get the sled to handle better!
The main take away from all of this is that many riders are using their Yamahas with an improperly adjusted rear suspension preload, if you do not weigh 175 pounds and have not made any adjustments to the coil spring length. The Monoshock rear suspension is primarily a comfort suspension and less capable of resistance to bottoming, thus the torsion spring versions in the RTX models which are more capable to withstand harder riding and resisting bottoming.

Once you get 50 hours on your Polaris IQ model, it will start flashing “SERVICE” on the LCD screen each time you start your sled. Some riders know what this means; do you?
This doesn’t mean that something has suddenly gone wrong with your sled.  Most Polaris sleds are delivered from the dealer with a 50-hour service indicator. When the timer hits 50 hours, you will see the screen display “SERVICE” each time the sled is started, or until the timer is reset. This is done by entering the service mode (two presses up on the green rocket MODE switch) and then you hold the green rocker SET switch down until the “50” (hour timer) first starts to flash, and then quits flashing (about ten seconds). If you want to change the number of hours between the SERVICE indicator coming on, when the “50” is flashing let off on the SET (down) green rocker and instead scroll from 50 to 250 using the MODE (up position) of the green rocker, or to the “OFF” setting just past 250 hours.

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.