Snowtechmagazine.com » Service & Tuning Notes

2009 Crossfire & M-Series Fuel Pump Recall

Bill — Tue, 10 Nov 2009 21:18:23 +0000

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.

Yamaha Monoshock Preload

Bill — Tue, 10 Nov 2009 21:17:01 +0000

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.

2.    Measure the (unloaded) length of the shock spring, from end to end.

3.    Set the sled back down on the ground and have the rider (with riding gear) sit on the sled.

4.    Measure the spring length again (loaded length).

5.    Calculate the difference between the two measurements. It should be 40-45 mm.

6.    If required, adjust the spring preload to reach the proper 40-45mm setting. ON sleds with threaded adjusters instead of cam adjusters, pay special attention to the minimum installed spring length (you do not want the spring to coil bind). Most Yamaha coil springs can only be set 10mm shorter than the factory setting.

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.

Polaris IQ Flashing “SERVICE”

Bill — Tue, 10 Nov 2009 21:15:34 +0000

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.

Ski-Doo Summit XP Transfer

Bill — Fri, 02 Jan 2009 20:59:28 +0000

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 Tips

Bill — Fri, 02 Jan 2009 20:57:26 +0000

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.

Polaris IQ Camber

Bill — Fri, 02 Jan 2009 20:56:51 +0000

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.

Oil Pump Calibration Drift

Bill — Fri, 02 Jan 2009 20:55:05 +0000

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.

Deep Snow Intake Suffocation

Bill — Fri, 02 Jan 2009 20:52:55 +0000

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.

Adding as much intake surface area as possible. High Flow intakes really helped out here.
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.
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.

Improving Fuel Economy

Bill — Fri, 02 Jan 2009 20:51:55 +0000

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.

IQ Snow Ingestion

Bill — Fri, 02 Jan 2009 20:51:21 +0000

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.