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How To Snowmobile Watercross for Beginners
by David Aksomitis
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.
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 4x4. 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.
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.
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.
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!
Enjoy your summer snowmobile activities. This article originally appeared in SnowRider Online Magazine in April 2001.
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