This is a followup to a question I posted a while back asking about
the existence of Water Seperators.
Thanks to alot of help from this newsgroup, I have compiled a list
of precautions snowmobilers can adhere to as to avoid fuel/water
What Happens if Water Gets Into the Fuel System on a Sled?
Generally, the water will freeze at some point and cause a fuel line blockage,
clogged fuel filter, or even plug up a jet in the carburator. These things
can leave you stranded due to fuel starvation, or worse yet, damage your
engine (i.e. lean condition due to plugged jet can melt down a piston!).
Root Causes for Water in the Fuel
For starters, I'll answer the question why/how does water get into
the fuel system. There are 3 primary sources:
1) The gasoline coming from the gas station or container has
water in it (i.e. bad gas).
2) Condensation of water on the surface of the gas in the tank
causes the water to sink to the bottom of the tank. Remember,
water is much heavier than gasoline, and since water and oil don't
mix (one is polar and the other is not), the water goes to the
bottom. Anytime the outside air gets warmer then the gas in your
tank (e.g. in the morning when the temp is rising or when you pull
your sled into a warm garage), water in the air condenses on the
surface of the gas (like a window fogging up).
3) Air pockets in the tank go from a balmy 30F in the day and down
to zero at night. Actual dew or frost can fall out of the air as the temp
Precautions to Take to Minimize Incoming Water
Now, let's look at how to minimize these sources (note minimize, it is
impossible to completely eliminate the water).
To address the first source of water, I have heard 2 good suggestions:
1a) Only fill a sled with gasoline from an outside container. Most gas
containers have screens in the nozzle. If the gas from the pump
has water in it, then it will collect in the bottom of our container
and freeze if it cold enough. Then, the screen in the container nozzle
will filter out the ice particles.
1b) There is a special kind of funnel that seperates water from the gas
thus not letting the water to flow through the funnel. This precaution
should work well if the water is not frozen in the pump/container.
I have not laid my hands on one of these funnels, but you can be
assured I will track one down and use it.
The 2nd source of water can be minimized by following these guidelines:
2a) Always fill your gas tank to the top before pulling it into a heated
2b) Make sure your tank is filled up before putting it away for the day.
Trailers are known to get quite warm inside, especially if they are
black like mine. In the morning, the temp is about as low as it gets.
When the sun hits a black trailer, the temp inside will raise much faster
then the outside air temp. So, the gas is then colder then the outside
air again causing condensation.
A full tank basically reduces the surface area of the gasoline exposed to the
air (i.e. a smaller window to fog up).
The 3rd source is relating to the dew and frost points. The main thing again
is make sure the tank is filled before the temp starts dropping at night.
How to Deal With the Water that Collects in Your Sleds Fuel System
Ok, so there is water in your tank. Everybody has some. Well, most of
it enters into your fuel tank one way or another. So lets start there:
1) Follow your sled manufacturer's instructions regarding the addition
of ***s to your fuels (RTFM). Generally, most manufacturers say
to add 1 to 2 oz or isopropyl *** per gallon of gas. What does
*** do, well it is semi-polar as far as its molecular structrure.
Thus, it lets some of the water get disolved into the gas and the
*** acts as a liason. So, you end up buring the gas/water/***
as a solution. If there is alot of water, then the *** tends to
collect in the water at the bottom of the tank and acts as an anti-freeze.
2) There are fuel dryers that absorb water from a tank. Some of these
do not work with ***, so they are best used for summer storage in
my opinion. Basically, they are something like a tubular tea bag that
you tie to your gas gauge float and keep in your tank.
If for some reason you can not discipate all of the water in your tank, then
you've got some problems now downstream. First customer, the fuel filter.
Now, this water can be frozen, slushy, or completely liquid. The first 2
forms normally will clog the fuel filter and the last form can get through it.
I believe the best thing to do is throw away the inline filter the sleds
come with, and replace it with a fuel/water seperator and filter assembly.
3) Use a fuel/water seperator and filter assembly instead of the stock
fuel filter. Racor makes a nice one that is perfect for this application
(Model 025-RAC-01). It has a clear bowl that you can use to inspec for
the presence of water. If water is in there, then you can drain the water
and be back in business. Alot of big diesel engines and boats (even
jet skis) come with fuel/water seperators. I am amazed that the sled
manufacturers have not made these seperators/filters standard equipement.
You can get for Racor product information from them directly at
1-800-344-3278. The filter assemblies cost less than $30. Also,
West Marine carries there product line, their web page is:
Now with your fuel filter/water seperator is in place, only good gas should be
moving on through the system. The only thing else to worry about is water
collecting in the fuel bowls on carburated engines. So, they need attention:
4) Periodically inspect the water/sediment traps on your carburators (if
so equiped). On Polaris engines, there is a hose running from the
bottom of the carburator that has a plug in the end (in 93 they were clear,
97's are a black hose, thanks Polaris). Remove the plug
and drain the gas/water from the carb bowl once in a while. Make sure
to follow your manufacturer guidelines for this procedure. Remember,
gasoline is very dangerous!
Well, I hope these tid bits help. I have experienced water problems in the
past, an have a vested interest in avoiding them in the future. For example,
it was -10F in Munising Michigan during a blizzard and the water my wifes
fuel filter killed her engine. Not a very convient time to go for a walk.
Again, thanks to all that contributed tips on addressing water problems.
Especially, the guys from Alaska.