Prepping A Snowmobile For The Off-Season
Every spring, many a snowmobile coasts to a stop at the end of the season’s last ride — and there it sits. In the yard all spring, summer and fall for the world to see. Unprotected from the elements, it degrades.
Fuel hoses harden, seat fabrics dry out and crack, and rust forms on internal engine components. Corrosion forms in the space between metal cross-shafts and tubes in the rear suspension, which causes those parts to bind. Decals crack and peel, and the shiny finish on the tunnel slowly turns into a dull, chalky layer of ‘blah.’ Snowmobiles deserve better.
Even if you aren’t that negligent, simply parking your sled in a garage and dumping a little fuel stabilizer in the gas tank isn’t enough to ward off sled wear.
Spending about an hour in the spring to prep a snowmobile for the off-season will keep it reliable and fun to ride well into the future, not to mention help retain its value. You’ll need a can of storage fogging oil, a few ounces of fuel stabilizer, grease, simple hand tools, aerosol lubricant and a nice place for the snowmobile to rest until fall.
Treat The Fuel
Treat the gasoline with fuel stabilizer to help achieve easier starts in the fall and to reduce the chance that the carburetors will be plugged with gunk. Gasoline contains solvents that make it volatile, but when those solvents evaporate, the vapors rise from the carburetor bowl and might cause some metals to corrode. That green gunk that collects in the bowl of a carburetor is remnant of fuel and corroded metal that ran down the body of the carburetor and settled at the lowest point. Fuel injected engines don’t usually suffer from this condition because throttle bodies, typically, are airtight.
Stabilizers are designed to reduce evaporation of solvents that make gas volatile. While using too much stabilizer won’t necessarily harm the fuel system, fuel additives inherently reduce the octane rating of fuel by “watering down” the concentration, so follow the directions on the container to add the correct amount of stabilizer in relation to how much fuel is in the tank.
Talk to someone from just about any crankshaft repair shop and they’ll say that coating the inside of a snowmobile’s engine with storage fogging oil is an essential step to prevent crankshaft failure. This thin layer of oil protects parts like connecting rods, rod pins, cylinder walls and crankshaft bearings from air and moisture, which will otherwise work together to cause corrosion that makes those parts susceptible to failure.
Gain access to the engine’s carburetors or throttle bodies by removing or disassembling the air box and pulling out the foam or air horns. Or, you might be able to just peel back the carburetor boots in order to give the fogging oil an unobstructed path from the can to the intake. Removing the air box varies from brand to brand and model to model. It’s fairly easy to access the throat of carburetors or throttle bodies on older sleds, but many newer machines are tricky due to tight spaces that are packed with wires, hoses and cables. Work carefully as you remove parts and make note of their orientation.
With the engine running, spray fogging oil into the engine. Spray the oil at each intake for a few seconds at a time, and then switch to the other cylinder while simultaneously pushing the throttle lever to keep the engine running slightly above idle speed. Continue to spray oil into the engine — alternating cylinders every few seconds — for about a minute, or until thick, white smoke comes out of the exhaust. Let it sputter and shut down. If the engine has carburetors, turn off the fuel switch and remove the drain plugs to let the gasoline flow out. This, in addition to adding fuel stabilizer, helps reduce the chance of problems with the fuel system in the fall.
Spraying storage fogging oil through the intake of a four-stroke engine will help protect the cam shaft, valves and other components in the cylinder head, but Arctic Cat, for example, specifically says not to fog its 1100cc engines. If you’re prepping a four-stroke engine for the off-season, check the owner’s manual to find out whether you should do this step. The manual might also suggest that you change the oil and filter. Two-stroke Ski-Doo sleds with E-TEC direct injection have a self-fogging feature.
Grease The Chassis
To help keep the suspension and steering systems working smoothly, pump a few shots of grease into each zerk on the chassis. This pushes out water from within the small shafts and suspension tubes, and fills those small voids with grease so moisture won’t collect inside the tubes during the temperature cycles of early spring and late fall.
Sleds built within the past few years generally have fewer grease zerks than earlier machines. You might find two or three in the rear suspension and a couple on the front end, but a sled from the mid-1990s, for example, could have six zerks in the skidframe and more than four on the front suspension. Use light from a bright flashlight to look under the engine for zerks on the steering system.
You can’t over-grease a zerk on a snowmobile. Pump grease into the zerk until you see fresh grease come out of the tube or shaft. Look closely and you might see water come out, proving that this is an important step of snowmobile summerization.
Protect Precious Metals
If you’re feeling ambitious, wash the sled with soap and water to restore its showroom shine. Washing is a must-do if the machine was hauled on an open trailer in order to remove corrosive salt and road grime. Spray WD-40 or similar, lightweight oil on metal surfaces: the exhaust, A-arms, rear suspension rails, chaincase cover, cylinders and cylinder head. Liberally apply the oil on those parts to put a barrier against corrosion, but make sure it doesn’t contact the clutches or drive belt. When you pull the sled out of storage in the fall, wash it with a light degreaser like Simple Green to remove the oily glaze.
Where To Park It
The specific location of where you park a snowmobile during the off-season can affect how well it weathers the humid summer air. Under a tarp in the front yard is probably the worst place to store a sled because that cover doesn’t provide real protection from the elements and it traps moisture, which can accelerate corrosion. A sled set on top of a sweaty, concrete floor isn’t good either, for the same reason.
Try to find a dry place indoors, like a garage or the loft of an outbuilding, and put a soft cover over the machine to protect it from dust. A few mothballs scattered under the hood and on the tunnel will help keep rodents away so they can’t gnaw the seat or other foam on the hood or airbox.
Elevate the rear end of the machine by placing a jackstand under the rear bumper, and then unhook the springs. Lift the sled and set the bulkhead on a wooden box or milk crate so the front suspension hangs freely, too. This relieves tension from the springs and helps them last longer, not to mention it takes weight off the track lugs so the tips don’t fold over.
Firing up an engine every few weeks during the summer keeps fuel moving through the carburetors and spreads a little oil through the engine, but it’s not adequate to ensure the best crankshaft protection. Letting an engine idle probably won’t get it hot enough to burn off moisture inside an engine, and it might promote even more water vapor to collect on the crankshaft and within the exhaust system.