How to Watercross Snowmobiles

Do you have an old snowmobile you’d like to take out on the water? No problem! While water skipping with an older snow machine is a challenge, you can stay afloat with some work.

Snowmobile watercrossSnowmobile watercross

Picking Your Water Crossing body of Water

Picking your body of water is important since you probably don’t have access to a retrieval boat like they use at competitions!

You want water that is shallow enough to walk across, with access to a tow vehicle along the edges. Of course you’ll need a long enough rope to get from the sled to your ATV or 4×4. We use a roll of 1/2? poly rope.

In addition you’ll need smooth entry and exit points. If possible it’s nice to have a short-cut off the water body as well for those who feel they can’t make it to the opposite end.

Watercross with the old Formula Z

Getting Your Sled Ready for the Maiden Voyage

You’ll need to remove the snowmobile seat for starters. If the foam gets wet it is never the same again, usually it hardens.

Any spare parts on the sled should also be removed: tools, belts, extra plugs, etc. Remove everything extra that will lighten the sled and couldn’t be used on the water surface anyway!

Oil injection snow machines should have the oil injection removed and use mixed fuel. The reason for this is that water enters the oil tank when you sink. Since the water is not healthy for your engine the tank would have to be dumped and dried out each time. This could be very costly, as well as messy and not healthy for the environment.

Since we run Rotax engines with rotary valves that need oil, we seal the rotary valve off by running a hose between the inlet and outlet points, leaving some oil inside [not too full – you have to leave room for expansion] and clamping it. Keep an eye on the oil level though, to make sure you don’t have any problems.

Snowmobile watercross

Track selection

On smaller horsepower sleds [i.e. 500 MXZ] the stock .85 track works well, whereas a paddle track would sink a sled with this size engine. A 700 engine will work well with a paddle track.

Tracks may also be reversed for better water bite. Simply remove your track and re-install it the other way.

If you’re using an older sled with bad lugs in the track, you’ll probably have problems staying on top of the water. On our 9500 we used a new style internal drive track with Everest suspension installed.

Getting Your Snow Machine on the Water

The first thing we discovered was that we didn’t require as much speed entering the water as we expected. When we hit the water too fast, the sled tended to bounce and ultimately sink.

Right now, depending on the traction of our entrance to the water, we take about a ten to twenty foot run at full throttle. This provides a smooth entry.

The first few feet in the water, while the snowmobile is accelerating, requires a lot of driver balance as the machine turns really easy. If you move your weight around the sled will flop from side to side. However, once you’ve reached full speed the snow machine becomes much more stable.

If you’d like to try turning your sled on the water, you will have to do different things depending on what type of sled you’re driving. For instance with our old 9500 you just put your weight to one running board and the sled turns in that direction. On the newer MXZ, you actually have to back off the throttle and accelerate while standing on one side of the sled.

Mach I snowmobile waterskipping

So you’re sinking!

The most important thing you have to do when you realize you’re going to sink is to kill the sled’s engine before it hits the water. Otherwise it will take in water, possibly causing damage to the crank. When a cylinder fills full of water it can’t compress it, so something has to break!

Since you’re in shallow water, just stand up and head for shore and your rope!

When tieing the tow rope onto your sled, attach it to one ski only. If you attach it to both you may bend your tierods.

Back on shore…

With much practice at starting wet snowmobiles we have found a few tricks. Once the snow machine is onshore, remove its spark plugs. Next, tip it on its side and turn it over with the starter rope. This does two things: the top cylinder drains faster to give you one that will fire sooner and it helps to drain the exhaust system as the sled won’t start if the muffler is full of water. It should take about a dozen or so pulls.

Set the sled back on its track. Pull the impulse line off the engine as this will help drain out the crankcase. Turn the engine over until water quits coming out of the impulse hole. Re-install this line.

Our sleds all have primers so we prime them to the point of being flooded with gas. A few more pulls. Reinstall plugs. Try to start. If it fails to start you probably have water in the carbs. This will depend on how long the sled was actually immersed in the water.

Remove the carbs from your sled and drain them. Reinstall and prime your sled again to start it. If it still fails to start, remove the plugs and turn it over some more – one pull with the plug holes open and one pull with fingers covering the holes. This helps to pull the water up and out of the engine.

We’ve found that the sled usually fires even though water is coming up the spark plug holes, so try starting again after several pulls. When your sled starts it will sound a little strange until it clears the water out of the engine and exhaust.

Now you’re ready for trip #2 across the water!

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