Here at SnowTech we are bombarded each year with box after box of new products for our staff to preview, review and analyze. So when a new bottle of something shows up, we are very skeptical, to say the least. Especially when it comes to additives, oils, anything in a bottle. But every now and then we find one that impresses us, and here we have one of those.
This time we have a fuel additive called “Star Tron Enzyme Fuel Treatment”. This stuff is fairly popular in the marine industry, and being labeled as an enzyme it got our attention.
This Star Tron Enzyme Fuel Treatment basically is a fuel stabilizer. Pour it in and the fuel should remain viable for over a year. This makes it an excellent choice for storage or for engines that are not used every month (which is about the shelf life of most fuel these days).
It also is an excellent counteragent for ethanol fuels, helping to keep water from forming a layer or causing problems. Bacteria, fungi, mold, and yeast have just met their match.

An enzyme is a biochemical catalyst. To catalyze something, the enzyme increases the rate of a chemical reaction.
Finding an enzyme that reacts with fuel is really cool. With all of the various EPA requirements, one never really knows for sure what they’re pouring into their tank. How fresh is the gas, how much ethanol does it contain, how much water is in there, what is the octane. You just don’t know. Fuel these days is a mixture of hydrocarbons (and other stuff) that consists of molecules of various chain lengths. Long-chain hydrocarbons, short-chain hydrocarbons, and all lengths in between.
The short-chain hydrocarbons are what make up the “light ends” in the fuel, the stuff that vaporizes easily and goes BANG. The long-chain hydrocarbons are the heavy stuff that doesn’t like to burn very well. Ideally, we don’t want too many of either of these, instead it would be nice to have more medium length molecules going into our engines for a more complete burn.

What you will most likely notice is how smoothly an engine will run when using this stuff. The hydrocarbon chain bonding is altered by the enzymes, so we get a more homogonous fuel than we would otherwise. Homogonous means the fuel is going to be composed of a more uniform chain length. Fewer heavy chains means cleaner burning fuel, with less carbon and soot. This product will help to clean carbon (yes, even dirty power valves) and the entire fuel system. The engine will run smoother, start easier, and there should be a slight but true gain in power and efficiency. And what is really cool is it will, to a degree, rejuvenate stale fuel.
Add an ounce of Star Tron for every three gallons for the first dose to shock the system, then back off to an ounce per six gallons. That means an 8 ounce bottle is good for 48 gallons of fuel after the initial treatment.
Add a bottle to start with, and then see what your usage is. If you use the engine all the time the fuel should stay fresh, but as soon as you get to the point the sled or whatever is going to be idle for a while, get some more Star Tron in there. Or, if it is at the end of the season, for sure give it a shot. The ratio isn’t all that critical, we’re told that overdosing isn’t harmful, and adding it every time you add fuel is going to help, but again, if you’re going to burn the fuel up quickly there isn’t going to be as great of a benefit in that you don’t need the stabilizer. Of course, you will still realize the running quality benefit and cleaning action, which is a good thing for power valve applications. Or, if you’re being forced to use 10% ethanol fuel, then adding it every time is going to be a good thing.
Star Tron Enzyme Fuel Treatment comes in several bottle shapes and sizes; the smaller 8 ounce bottles are handy and easy to carry. You will see the difference in your spark plugs and amount of carbon on the power valves, and where you will really see it is in low RPM situations like two-stroke trolling motors. Instead of the rough running chuga-chuga that you’ve been used to, you should notice smoother running and easier starting.
Where can you buy it? Most every marine dealer carries it, but it is also found in most Wal-Mart stores, Fleet Farm (Wisconsin based) and can also be ordered on-line (get a case #14308 of six of the 8 ounce bottles). It comes in 8 ounce, 16 ounce, 32 ounce, whatever you want. It is cheaper per ounce in the larger quantities, of course, but you will usually pay about $25 for a 32 ounce bottle (which treats 192 gallons) which comes to about 13 cents per gallon – cheap insurance against fuel related problems.

Since Polaris has suspended the big-block 755 and 900 engines for this season, your choices to build a rockin’ 2007 Polaris mountain sled are based on the potent small-block motors; the 600 H.O. and the all-new Dragon. Problem is, the Dragon 700 was only offered in the spring and was very limited in quantities.
Solution? Turn a 600 H.O. into a fire-breathing Dragon-kicking 727cc. The Polaris engine gurus at Starting Line Products have developed a very reliable and well-mannered big bore kit for the little six, and we’ve spent some time on it carving up the snow in Idaho.
The kit utilizes SLP cylinders to provide enough room for big transfer ports and adequate cooling for no-compromise performance. Basically, the complete kit includes cylinders, head, pistons and rings, wrist pins, power valves and all gaskets. You’ll also need an SLP single pipe exhaust system, SLP Airhorn Intake Kit, Flow-Rite Intake Pre-filters, V-Force reeds and clutching changes to make this thing freakin’ scream.
The result is far more than just Dragon-like power; the 727 Big Bore Kit will bring the output up to 150 HP. Considering the lightweight nature of the RMK and Switchback 600 H.O. models, this much power with this little weight makes the 727 a force to reckon with. It is agile and flickable, with instant and explosive throttle response for a pure-Polaris screamer.  We found it to easily be a good match for a Summit 800; not quite as stout down low but with more power than the Rotax on the big end. The large volume ceramic-coated single pipe exhaust provides broad torque and a wide powerband. The large volume canister silencer helps keep noise levels in check, and the ceramic coating stabilizes exhaust temps quickly and reduces underhood heat.
For those who don’t want to spend the bucks for the all-out 727 with new cylinders, we also tested the SLP 660 Big Bore Kit for the Polaris 600 H.O. This kit uses OE cylinders, modified to make room for the larger pistons, with the appropriate porting performed by the SLP wizards whose work is often copied but rarely (if ever) duplicated. While not as wicked as the 727, it provides a very effective performance gain as well for less $$$, making it a great value. Like the 727, the 660 Kit is best matched to an SLP single pipe exhaust system, SLP Airhorn Intake Kit, Flow-Rite Intake Pre-filters, V-Force reeds and clutching changes. Power? 136 HP. Just what you need to run with the bigger cc sleds but with less weight. More importantly the package has stock-like mannerisms in that it has a broad tolerance band  – it isn’t peaky or in need of constant tuning to run great.
With either of these kits, SLP provides OE-like specifications for clutching and carburetion requirements for various elevations and temperatures – and they work.
For 2007, Polaris also offers the 600 H.O. with Clean Fire Injection (CFI). SLP is currently working with these new CFI models and they expect to have similar products available for them in the near future. Right now, the kits are fully calibrated for the carbed 2006 & 2007 RMK & Switchback models. The 727 is only offered for high elevation applications, where the 660 can be run anywhere.
And since the 600 H.O. engine packages are in the IQ chassis for the short track models, most all of the RMK mods will now cross over and bolt right into the short track sleds as well. Calibrations for these models are also being finalized, so check on availability for your specific model.
The 727 Big Bore Kit goes for $2612 with new SLP cylinders. The 660 Big Bore Kit (modified OE cylinders, exchange or yours sent in) goes for $1350; the SLP exhaust system, SLP High Flow Intake and V-Force reeds are not required, but highly recommended with this package. Calibration details are provided for both options. For details or to order now so you’re ready when the snow flies contact: Starting Line Products at 208-529-0244, or visit startinglineproducts.com

***After reading this article, be sure to read Diamond Drive Service CAUTION***

With an increasing number of Arctic Cats now fitted with the radically-different Diamond Drive gearbox, the number of questions and curiosity surrounding these units is increasing.

First off, about the only service the units should require is to drain and replace the lube in the gearbox. This should be done, at a minimum, annually (once a year). When performing this service, we want to carefully measure the amount of fluid that is drained and to inspect the fluid so we can determine if there is moisture entering the case. Ideally there should only be three ounces of lube in the case; some units could have slightly more, but anything over four ounces can cause problems.

You can get the lube right from an Arctic Cat dealer, or better yet you can get an entire kit from the designers of the Diamond Drive system, Black Diamond. Their lube kit, that includes a precise amount of higher-quality synthetic lube than what Cat uses, along with a new o-ring for the drain plug and a tube of gearbox sealant so you can remove the cover and perform a full inspection. (Do NOT use chaincase lube or you will pay dearly for that mistake!)

If all you want to do is replace the lube, you can do that, too. Flip the machine up on it’s right side and you will find a drain plug on the lower rear of the gearbox behind the drive shaft up inside of the tunnel (on the first year ZR 900s it’s down under the secondary clutch on the other side of the gearbox). Have something ready to catch the lube (a measuring device like a Ratio-Rite works good) and remove the drain plug. Once all of the lube has drained (it is slow to drain, as the gearbox is vented through the airspace around some of the threads) you will want to measure the oil once it is done draining as this will indicate if we are losing fluid through a leak (this happened to one of our 2006 Crossfire 700s).

We’ve heard a number of units may have seals that were installed backwards during assembly at the factory. This can allow water to enter the gearbox, and can lead to problems like what we experienced on our 2005 F6 this past season – “freezing” of the gearbox when it gets cold. It could also lead to excessive pressure in the gearbox, causing a “hydro lock” and, of course, rust. If the lube has a yellow appearance to it, there very likely is water entering the gearbox.

Once the lube is completely drained, place the sled on it’s left side. Here is where the trick starts – you will have to put a hose on the bottle if it is not equipped with one, and direct it into the hole. Don’t spill any, if you do, determine how much you spilled and only add that much. Do NOT overfill the case, this will cause big problems! Replace the plug and you’re done.

We’ve also heard a small number of units slipped out of the factory with zero lube in the gearboxes. If you got one of these, you wouldn’t have made it more than a couple of miles and the gearbox would have failed. But if you picked up a 2005 unit and haven’t used it yet, it would be wise to verify there is actually fluid in there before blasting off on your first ride, only to be seriously disappointed. Granted, not many units got out with this condition, but strange things happen when we’re talking about mass production on an assembly line.

You can also upgrade many of the secondary clutch components with higher quality, better fitting and more secure components from the aftermarket. Both of the threaded plastic adjusters that fit into the secondary can be replaced with billet pieces that will not move or break like the plastic pieces, providing more security to the belt fit. Realize the outer piece has left-hand threads on some 2005 and all 2006s, while the older units had right-hand threads (less secure due to the direction of rotation of the clutch).

Special thanks go to Black Magic Racing and Black Diamond for their assistance in preparing this article.

***After reading this article, be sure to read Diamond Drive Service CAUTION***

All of us own some sort of seasonal vehicle that has a battery. And, most of us have learned (the hard way) what happens when these lead-acid batteries sit unused for months on end; they’re dead when we go to start the vehicle and they don’t last very long. Do you replace batteries earlier than you should? This is a problem with ATV, PWC, marine, motorcycle, lawn equipment and snowmobile batteries. You use them for a few months, then they sit.

All of this can be avoided by connecting a “smart” battery charger to the battery, either on a scheduled basis or for the entire storage period. The latest battery chargers can extend the life of all of your batteries and save you a ton of cash and headache in the process.

And, chances are you still use a “stupid” high-current charger for your boats and cars and trucks. Get with the program! Everyone who owns a vehicle with a battery needs a “smart” charger. We’re not talking simply getting a charger with “float” maintenance; that’s a start, but there is so much more “intelligence” now available.

Over the past few years SnowTech has introduced you to a couple of excellent small battery chargers that are well suited for use on recreational vehicles like snowmobiles; first, the Battery Tender Jr., and then the outstanding Optimate III desulfator/charger offered through all Yamaha dealers.

Here is a new battery charger that is also worthy of your consideration; the CTEK line of chargers. CTEK is the best-selling battery charger in Europe, claiming to be “The smartest battery chargers in the world!” They’re from Sweden, and are just now introducing their chargers to the U.S. market.

The CTEK chargers are smart in that they carry a sophisticated program sequence in testing, charging, and maintaining your batteries. They offer chargers in three “sizes”; the US 800 with 0.8A of charging power, the Multi US 3300 with a switchable 0.8 or 3.3 amps of charging power, and the top-of-the-line Multi US 700 that can handle pretty much any 12V lead-acid battery you throw at it, along with most any other kind of 12 V DC battery. All of these chargers feature a “desulfation” mode that recovers, or “wakes” a sulfated battery that no longer accepts a “normal” charge.

The one we tested was the Multi US 3300, as it can be switched from a low current charge that is ideal for smaller (<14 Ah) to a high-current charge for batteries in the 14-90 Ah range (this includes all but the largest automotive and marine batteries).

The Multi US 3300 utilizes switch mode technology, a 4-cycle intelligent process for battery maintenance and charging:

1. Desulfation:Recovers or “wakes” a sulfated or under-charged battery
2. Bulk Charge: Begins charging at 0.8/3.3A
3. Absorption:Applies peak charge at 14.4/14.7V until fully charged
4. Pulse: Sends out current pulses for charge maintenance

You pretty much hook it up to the battery you need to charge or maintain, select the mode (small or large battery for proper charge current) and the charger fires up and analyzes the battery and decides what to do. A large number of batteries that one may have previously discarded because they were “bad” can actually be recovered and kept in service for even longer. While the chargers can’t fully recover every single old battery there is, we’ve been impressed with the speed and capability of the CTEK Multi 3000 in its ability to recover and maintain the snowmobile, watercraft and marine deep cycle batteries we’ve tested it on so far.

Its patented technology protects against sparks, short circuits and reverse polarity, and it does not damage sensitive electronics with “dirty” charging; you can leave the battery connected in the vehicle. You can pretty much leave it hooked up for months on end, the battery will be kept in tip-top shape and be ready when you are.

Another benefit of the CTEK 3300 is its weatherproof construction; its fully-sealed design is dustproof, splashproof & weatherproof, allowing it to be approved for outdoor use.

A unique feature is the addition of a higher-voltage charging mode, said to be better suited for use in colder temperatures. This “Cold weather boost mode” enables faster recharging in the coldest winter months by increasing the charging and target voltage to 14.7 V, making it ideal for our winter vehicles.

The unit is sleek and compact in size, and is lightweight (1.1 lbs.) and easy-to-carry. You don’t need a small charger for your sleds and other toys and a larger charger for your cars and boats, this one will do them all.

A quick-connect option eliminates need for reconnections in hard-to-connect applications. You can clamp onto the battery with the spring-clips, or you can attach a wiring harness to each battery you own and simply use the quick-connector plug to plug into any of them.
They work with virtually any lead-acid battery: Flooded, Maintenance-free, Gel, AGM. The higher-voltage Cold Weather Boost Mode is also recommended for many AGM batteries like Optima, Maxxima and Odysses, while many Gel batteries prefer the lower 14.4 V of the standard bulk charge mode.

The smaller US 800 only charges at the lower 0.8 A, so it is best suited for use on smaller recreational batteries and isn’t as good as the 3300 for the lager dual-purpose of also charging automotive and marine batteries.

The larger Multi US 7000 adds a “float” charge sequence to the pulse maintenance, as well as an automatic recondition mode to recondition deep-discharged batteries. This unit is best suited for the largest batteries found in RVs, larger boats and trucks with a full 7 A of charging power.

Sold at specialty retailers, the Multi US 3300 battery chargers are now available throughout the United States for $69.95. For more information about the CTEK Multi US 3300, call (330) 963-0981, e-mail usinfo@ctek.com or visit www.ctek.com.

One of the finer pieces of gear we got our hands on last season was the new Ski-Doo Pro Gear Bag. The Ski-Doo accessory people took some time to demonstrate all of its neat features to us, and we must admit we were impressed. You could instantly tell there was some thought that went into the design, more so than the run-of-the-mill gear bags most of us used to use. Things like a roll-out mat to stand on while getting suited up and changing from shoes to boots. Or the boot compartment with drain holes so the bottom of the bag isn’t holding the water. Or the fleece-lined helmet compartment so your face shield or goggles are in contact with a soft fabric, not getting abrasion from a rough nylon. There’s even a slick tool compartment, ready for you to fit your essential tools into. Very cool.

The Pro Gear Bag is fairly huge, with ample room to fit your boots in their own place, the helmet in another, and the jacket and pants in the main middle “cavernous” center compartment. While not the largest gear bag available, it is fitted with large diameter inline skate wheels, so it is a “roller” bag that also meets FAA rules for airline luggage. There’s even a telescoping handle so you can be stylin’ through the airports, or at least rolling your bag through the motel hallways instead of having to lug it the whole way.

Just because it says “Ski-Doo” on the side doesn’t mean it can only be used for sledding, it serves double duty as an excellent gear bag for ATV and dirt bike riders as well. We’ve rarely ever seen a better-designed gear bag from anyone, if ever.

The Ski-Doo Pro Gear Bag is available at any and all authorized Ski-Doo dealers and retails for $189.99 USD ($209.99 CDN).

The Superclamp II is the second generation lever-action tie down system from R. Bowmann Industries. This composite (fiber-filled thermoplastic) tie-down consists of a deck hook (loop, actually) and a tie-down bar now made from plastic with a lever that you pull from the edge of the trailer, not having to reach in towards the middle, with positive clamping force.
You place a clamp loop in the bed of the trailer, either screwed into the hole in the bed or mounted in the slot. From the edge of the trailer you engage the loop with the hook on the bottom of the tie down as you center the tie-down across the top of the skis just in front of the spindles and pull the lever. Install the locking pin (or your own lock for added security) and that’s it.

No more cranking a screw-type tie-down. The lever is big and easy to grab with gloves on and flat out works. You can “lock and load”, or make that “load and lock”, in a matter of seconds instead of minutes. Unloading is just as fast, when you’re in a hurry to get out there and go for a ride. Pull the pin, flip the lever, slide the tie-down over slightly to disengage the loop, lift it out and away we go. It’s that quick.

A top-center mounted height adjuster gives you the ability to adjust the clamping force and hook height to match different ski heights. Earlier problems with engaging the hook on some skis has been eliminated with slightly taller loops. You pretty much set it once and forget it, as long as it is used on the same sled or type of skis. Different ski heights typically require quick adjustment to get the proper clamping force.

We’ve been using the Superclamp ever since its early stages, not much past prototyping. Since then, we’ve witnessed constant tweaks and upgrades to the system that have improved the function and application of the tie-down. Silicone pads on the bottom ends protect your skis.

Compared to the earlier metal Superclamp, the new Superclamp II is far lighter (actual weight here) due to the thermoplastic and is plenty strong with its encapsulated gull wing structure. There is a slight amount of flex to the bar, but not so much that it would seem to effect security. The flex is helpful in preventing you from over-tightening the system, which was easier to do with the metal bars.

Bowmann also offers a similar tie-down for the rear of the sled, a shorter version that also uses lever-action to positively clamp the machine to the trailer deck surface.

Is the Superclamp II better than the tie-downs that come on some of the new trailers? We say yes; our test riders prefer the Superlcmap II to the OE tie-downs for the smoother lever action and ease of use, especially when installing the locking pin.

The Superclamp II retails for $139.95, and the Superclamp II Rear goes for $109.95. Extra deck hooks go for $12 each. Offered through many dealers and distributors such as High Performance Engineering, Starting Line Products, or for more information call
403-203-2210. You can order the Superclamp II Tie-Down System Online at www.spiralusgroup.net

Have you ever been working on your sled when someone wants whatever is in front, or right behind you ? No big deal if you’re using this lift. Just roll it out of the way or to where you want it, plug it in, push a button and up it goes. Everyone who has used this lift says this is one of the best things about it. Even when up in the air moving it around is no problem with wheels big and strong enough to easily roll over small rocks and cracks in the floor. It is very stable in the up position for all types of repairs. The motor is strong and quiet and we have yet to stall it out lifting the heaviest sleds or ATVs. The control box is remote for rear skid removal and replacement. You can actually raise and lower the lift to exactly the right position when putting bolts back in place while along side the sled. When through using it, it lays flat, out of the way, as the handle is also removable for storage. In the summer sleds can be stored in the full upright position with the suspenions fully unloaded and taking up no more room than the sled itself. After using it for a season, our conclusion is that this is one darned good lift – plenty good enough for constant use in a heavy traffic dealership. In a perfect world we would ask for a longer power cord so we wouldn’t have to dedicate an extension cord for its use. If you’re in the market for a great, all purpose lift check this one out. It’s from Performance Products, LLC @ $599.95. Call 1-877-687-2301 and ask for Kurt or Keith.

There has to be over 100 different injection oils offered for snowmobiles, some very good and some not so good. How do you know which is which?

One injection oil that we’ve been using for the past two years comes with little fanfare and a not-so-fancy label. “Fowler 2 Cycle Extreme” doesn’t boast huge advertising budgets, nor do they throw tons of cash at promotions. So when we got a couple of cases sent to us for evaluation, we seriously doubted if it was worth pouring into one of our very expensive snowmobiles. We’ve tried oils in the past that gummed up the power valves so bad and made the spark plugs look terrible with gummy deposits that we didn’t want to see what the rest of the engine looked like. We tend to prefer full synthetic oils, but there are some really good semi-synthetics that can be bought for much less cash than full synthetics. Maybe we should give this one a shot.

Our dedicated test sled for this project was a 2004 Polaris Pro X2 700. We chose a Polaris simply because of all the gummed up power valves we hear about. We even sucked out all of the original oil from the tank when the sled was brand new so we could get a good read on this stuff, and then ran this oil (exclusively) for over 1500 miles.

In all honesty, we really expected this to be just another oil that stunk and gummed things up. Much to our surprise, the 2 Cycle Extreme didn’t really smell much at all. There wasn’t any sort of perfume to it, not much aroma or smoke, it was almost as “smokeless” as any other oil for that matter. Maybe not as clean as some of the more expensive fully synthetics, but quite impressive.

Down below –30, we found it to pour quite well. Day after day, the plugs looked good, and the valves stayed pretty clean. This oil actually seemed to be burning pretty good. At only $16.95 per gallon, we started to pay attention. We had found an oil that delivered a nice balance between performance and cost.

One measure we’ve always used to establish a baseline of protection capability is if an oil meets the Japanese and European specifications; JASO-FC (Japan) and ISO-EGD (Global/Euro). 2 Cycle Extreme meets or exceeds both of these standards. This also got our attention, as we knew it had to be fairly good to get both of these ratings. These certifications require high temperature, thermally stable additives and special base oils specifically designed to reduce piston scuffing while minimizing exhaust port carboning and smoking.

Fowler 2 Cycle Extreme is distributed by Fowler Distributors of Bloomington, Minnesota. According to Fowler, 2 Cycle Extreme is a synthetic blend, low smoke high performance oil that reduces piston scuffing by over 90% compared to ashless TCW-3 formulas. It has a pour point of –60, and offers an SAE Grade 3 miscibility/fluidity with gas.

They only add a dilutent to the highly refined petroleum base oil and synthetic additive package to get the super-low (-60) pour point. Many injection oils boast about a –40 pour point, but we had –44 in central Minnesota this past season and you can do the math. This oil will continue to protect at temperatures that many other “good” oils fall by the wayside.

Their pitch is simple. The oil is “simply pure oil”. No chemical mysteries. No magic additives. No bull. Rather, they offer a highly refined petroleum base oil and the highest quality synthetic additive package that burns off completely and with a minimum of smoke; exhaust smoke is reduced by a claimed 25-55%, and from what we’ve experienced, this seems to pretty much be accurate.

Since the oil burns off so completely, there is very minimal carbon build-up anywhere in the engine from the power valves to the heads, rings and exhaust pipes. Since there are no unrefined ingredients that don’t burn off there’s no gum or varnish to stick to anything.

The theme continues with no perfumes, no un-needed chemicals, and no offensive stink. Only completely burned off oil. Our eyes, nose and throat tell us this is also pretty accurate. One of the best tests is when you fire up a sled loaded in an enclosed trailer (doors open, of course). We do this all the time, and wait for a few moments to let the water jackets warm up slightly before throwing a load at the engine. This is when cheap oil smoke can choke you, and is when you can tell the difference between oils that burn completely and those that don’t. Firing up the Pro X2 with 2 Cycle Extreme in the enclosed trailer wasn’t much of an issue. In actually smokes and smells less than most OEM oils.

OK, we’re not saying this is the highest quality oil you can buy for your sled. We are saying we’ve used it for two years and have experienced good results that, when compared to the retail price of $16.95 per gallon ($101.70 for a case of six gallons) makes it one of the better oils you can get for that kind of money. We call that “value”. Just good protection at a good price.

Order a case of six gallons and Fowler will ship it FREE. We were pleasantly surprised, and suspect you will be too. Call them at 800-843-1424. Some dealers carry it, and maybe more will if you ask for it.

Last year we introduced you to the new FOX FLOAT AirShox that replace the traditional heavy coil spring found on ski shocks absorbers with an adjustable “air spring”, an air chamber that replicates and improves upon the spring action of the coil spring.

Typical shock absorbers on the front suspension use coil-over springs to store and release the energy of the bumps, with the shock absorber controlling the rate of absorption and subsequent release of the energy stored in the springs. This has proven to be economical, but steel wire coil springs weigh approximately six pounds on a typical snowmobile. The AirShox eliminate the heavy coil springs, along with about six pounds of unsprung weight (what’s lighter than air?) for a HUGE difference.

FLOAT stands for Fox Load Optimizing Air Technology. This is pretty much a FOX high-pressure internal floating piston shock with a second tube covering the previously-exposed shock rod; an adjustable air volume sleeve on the outside of the aluminum hard-anondized shock body.

Inside you’ll find an adjustable force-sensitive shim damping system (just like we’re used to) and a hard-chrome shaft. They are, of course, revalvable and rebuildable. The FLOAT design also incorporates FOX’s exclusive “Samurai Wiper”. This patented scraper-lip technology virtually eliminates the entry of water contaminating the oil in the shock, which translates to fewer rebuilds and more riding time.

Now for 2005, Arctic Cat offers the FLOAT AirShox as standard issue on their King Cat, M-Series Limited models, and Firecat SnoPro models. In addition, Yamaha has added the FLOAT Air Shox as an authorized Yamaha accessory for many of their four-stroke models.

How do they work? We installed a set onto one of our long term test sleds, a early-build 2004 Arctic Cat Firecat F6. Installation was very easy, a matter of unloading each ski and removing the shock bolts and shocks. Installation consists of adapter bushings and the shocks, and re-torquing the bolts.

The AirShox are adjustable via an air pump, so there is a small amount of initial set-up where you calculate your starting air pressure (pre-load) and using the air pump to apply this pressure to the FLOAT chamber. Since our riders tend to be heavier than the average bear, we set our AirShox to 60 psi (based on the formula provided by Fox, 50 psi standard for the Firecat plus 10 psi for added rider weight).

Our test riders immediately noticed the difference. The AirShox provide a progressive force vs. travel curve, compared to a straight rate nature of coil springs. What this means is the AirShox are a bit softer and more compliant for about the first 60% of the suspension travel, but quickly build force during the final 30% of shock stroke (and suspension travel). This virtually eliminates harsh bottoming of the suspension, and from what we experienced provided a “bottomless” feeling to the front suspension.

Adjustments in air pressure simply move this curve up and down. While we experimented a little with higher and lower air pressures, we found 60 psi to be just right for our trail riding. The factory-set 50 psi is intended for riders in the 180-190 pound range, and would provide excellent all-around performance for the majority of riders.

Almost everyone asks about the durability of the air spring, and if changes in temperature affect them. Theoretically, if you set the air pressure in the garage at +60 and go out and ride the sled at –20, there will be a change in air pressure just like the pressure in the tires on your car, but in practice this simply wasn’t an issue for us. Once we decided upon 60 psi as being high enough so it didn’t bottom and wasn’t harsh, yet low enough for a compliant ride, we left the pressure alone. We checked the pressure every couple of weeks with no change. They held their pressure all season long, and continue to do so on the shelf to this day. Pressure loss seems to be a moot point.

When checking the pressure of the shock with the pump, it takes a couple psi to fill the hose on the gauge so take this into consideration. To increase the pressure you stroke the pump. To decrease pressure, you press the pressure release valve. Very straight-forward and simple.

Do you have to carry the rather delicate air pump/gauge with you? We didn’t. Fox suggests carrying it with you on the first ride, but we started out cautiously and quickly discovered our initial settings were more than adequate for trail use.

FOX calls for routine service of the AirShox, just like any high-performance shock absorber. The air pressure should be checked at least once every month. Air sleeve maintenance should be performed at least once a year, and is something that most of us can do. Detailed instructions on this are provided in the owner’s manual, consisting of minor disassembly of the air sleeve, cleaning, inspection and lubrication, all fairly easy if you’re capable of something like performing track tension and alignment.

The IFP portion of the shock should be rebuilt (by a qualified technician due to the high-pressure nitrogen) every 3000-5000 miles. The FLOAT AirShox offer the highest quality materials and coatings Fox offers, so they’re far more durable than the Fox shocks of years past, and water ingestion appears to be greatly reduced on their latest offerings.

All of our worries proved to be unfounded, as the FLOAT AirShox performed exactly as we had hoped for. They reduced the already light F6 by six pounds, and this was all unsprung weight. Yes, you do notice six less pounds of unsprung mass. The suspension action is more compliant in the stutters AND nearly bottomless at full stroke. The air pressure didn’t vary enough to matter, and they proved most durable. This year we will be adding FLOAT AirShox to more of our test sleds. We view their being offered by Yamaha and Arctic Cat as evidence they’re worthy of your consideration. We suspect this will quickly become the new standard in mountain sled front suspensions for the weight, performance and durability.

All FLOAT AirShox will come with a FREE 90-day revalving guarantee and a 1-year limited factory warranty. Each FLOAT AirShox system will include two front ski FLOAT AirShox (with mounting hardware) and a FOX HP Air Pump. Kits are currently available to fit many popular performance and mountain sleds. Retail pricing is $895 per package, which includes two FLOAT AirShox, the pump/gauge and all hardware/bushings need for your installation. To order contact your authorized FOX dealer (Carver Performance at 888-349-7469 / www.carverperformance.com) or call 1-800-FOX-SHOX (www.foxracingshox.com).

Last season we told you about a new set of RAD Valves from Boyesen that had been developed specifically for the big-block Polaris twins.
Previously, Boyesen offered what was called a #63 version of their popular dual-stage RAD Valve design, but this version left some performance on the table. Boyesen, along with the help of Hot Seat Performance, set out to improve upon the #63 RAD design and came up with the #65 that was first available in limited quantities early last year (2003), and was offered full-force for the 2003-2004 winter season.
Well, the jury is in, and the #65 RAD Valve has been very successful. So much so, that Boyesen has had a difficult time keeping up with the demand. “We can hardly make them fast enough!”
For years, Boyesen RAD Valves have been the reed of choice in the motocross world and are quickly gaining acceptance in the snowmobile market. Like other Boyesen reed designs, they utilize the Dual-Stage Pro Series Reeds (also available to fit your stock reed cages for most every snowmobile with reed intake). This design combines a super-sensitive (lighter) carbon fiber reed as the top layer, with a durable fiberglass bottom reed. The lighter, top reed responds quicker and provides a crisper throttle response at partial throttle positions and lower engine RPMs. The stiffer, bottom reed is “ported” to provide maximum airflow and horsepower at higher RPMs.
The benefits of this dual-stage reed design is a package that better responds to both low speed and high speed airflow, resulting in more power and improved responsiveness across the entire powerband.
Then we get to the RAD Valve cage design. Each Boyesen RAD Valve is a solid, seamless one-piece casting. No distortion, no loose inserts or parts to rattle into the engine. Each valve fits perfectly with your stock manifold. None of this plastic like the OEMs use, which trade off some performance for cost savings.
According to Boyesen, their RAD Valve provides aerodynamic directional dividers that channel the incoming fuel-air charge for increased intake velocity. It not only sounds good, but it works.
What we notice is the dimensionally precise construction of the aluminum cages and the perfect fit. Never do you need to cut and destroy part of the stock intake boot to get them installed. Gaskets are included with each RAD Valve, and installation is as easy as removing your airbox and carbs. Reed durability has been excellent in our experience, and if the price of the entire cages is too steep then consider just installing the Power Reeds in place of your stock ones as a “Stage 1” improvement (this is true for any sled that needs a new set of reeds).
We’ve used various RAD Valves over the years, but never have we experienced such a profound improvement as the #65 RAD Valves. They technically replace the previous #63 RAD Valve for all Polaris twins, and the bigger the engine is the more noticeable the difference. While they work just fine on a stock engine package, anytime you begin to increase the airflow on a Polaris big block the RAD Valves make more and more of a difference. As you make more airflow mods to your motor (intake and exhaust), the stock reeds become more of a restricting factor the further you go.
Required jetting changes are minimal. If your sled is currently jetted properly, start where you’re at when you install the RAD Valves. They pull more air and fuel, so changes (if any) will be minimal. If you have stock jetting installed, drop the mains one size and start there. We’ve found this to be very accurate. You won’t have to do a bunch of tuning if the RAD Valves are the only thing you’re changing from a known working set-up.
Right now, our set of #65 RAD Valves are installed into our 2003 Polaris RMK 800 that has been tweaked even further with several intake modifications from Starting Line Products (Air Horn Kit and Flow Rites) and a SLP Single Pipe Exhaust system, forming a potent combination that’ll bring a smile to most every RMK owners’ face. This baby rocks!
Boyesen even goes as far as to provide a written guarantee; “You will experience increased power and throttle response. If you are not completely satisfied with any Boyesen product, return it for a full refund.”
The #65 RAD Valves for Polaris twins will cost you $268.75 (retail) for the set of two complete cages. If you want just the Power Reeds that’ll fit your stock Polaris twin’s reed cages (part #568) that’ll run only $80.09. RAD Valves and Power Reeds are available for most every reed intake snowmobile (and motorcycle) ever built. Call them at 800-441-1177 or order from one of many dealers/distributors, including High Performance Engineering (800-451-5268) or Hot Seat Performance (651-982-0600).