It's amazing what you can pick up if
you hang around a snowmobile repair and hop-up shop long enough.
This fall we were hanging around
Powerhouse MotorSports (http://www.powerhouseusa.com/) in Lindon, UT,
and Matt Hasara, one of the owners of Powerhouse and the head wrench,
was talking about what areas of a snowmobile many sledders tend to
neglect over the course of a winter riding season.
So we asked Hasara to provide details
on how to properly maintain those specific areas he was talking
about. Here are Hasara's maintenance tips.
All Mountain Sleds
Regularly check the hifax on your
snowmobile during the winter season, regardless of the brand or model
If you can get the open end of a 13mm
wrench over the hifax, then replace the hifax. Be sure to check the
hifax in several different spots along the rail. If you can't get
the wrench over the hifax, you're good for a while.
Change the gearcase fluid in the ACT
Diamond Drive. Hasara recommends changing the Diamond Drive fluid
every 500 miles or at least twice a season, "if you want the
Diamond Drive to last."
Clean fluid helps the Diamond Drive to
last longer while debris in the used fluid accelerates wear on the
planetary gears, which can cause it to fail, he explained.
All you need to change the DD fluid are
some basic hand tools.
1. Remove the secondary/driven so you
can get to the gearcase.
2. Remove the oil fill level plug and
withdraw a small amount of oil from the gearcase. If you see metal
shavings or bronze-colored shavings in the oil, that's a sign that
the thrust washer on the planetary gear is failing. If that's the
case, the gearcase has to be rebuilt and you're going to want to
head to your dealer to have this handled.
3. If there are no shavings in the oil,
then you can go ahead and flush the Diamond Drive and replace the
used fluid with clean Diamond Drive gearcase fluid.
4. With the oil fill plug removed, pour
the entire contents (6 oz.) of a bottle of ACT Flush Fluid into the
5. Fire up the sled and rev up the
engine to mix the fluids, which helps the cleaning process. You only
need to do this for a couple of minutes.
6. Open the oil drain plug to drain the
used fluid and flush fluid. Let the gearcase completely drain. Put
the drain plug back in.
7. Replace with new Diamond Drive
gearcase fluid. Non-reverse models (mechanical reverse on 2006 and
earlier models) use 3 oz. of gearcase fluid while 2007 and later
models (with electronic reverse) hold 12 oz. Put the fill plug back
8. Prior to putting the secondary back
on, Hasara recommends checking the O-rings on clutch bolts on the
primary clutch. If they're damaged or missing, it's time to
replace them. If the O-rings are missing, the clutch weight will
shift and drag on the spyder.
9. Put the secondary clutch back on.
Clean the exhaust valves. More
specifically, this Hasara maintenance tip deals with those RMKs that
have exhaust valves.
This is a good thing to do as a part of
the preseason prep on your snowmobile. And then every 500 miles do it
Basic hand tools are all you need to
accomplish this task. It's a fairly easy task so you don't need
to be an expert mechanic either.
As a side note, Hasara said it's been
his experience as well as the advice from other mechanics, that
Polaris Gold is best for not gumming up the exhaust valves. He added,
however, that "pretty much any oil is going to gum up the valves
The reason for this is that excessive
carbon buildup on the exhaust valves can cause the valves to stick,
causing the sled to lose power.
To clean the valves:
1. Remove the exhaust valves assembly.
Remove the two bolts that are parallel to the motor. The other two
bolts hold the cover that holds the bellows and springs.
2. Once you remove the housing, inspect
the gasket. If you accidentally tore it while removing the housing or
it's damaged in any way, replace it.
3. Pull the power valves out. First
spray the valves with carb cleaner or brake cleaning fluid to loosen
the carbon buildup on the valves. Then scrape the buildup off the
valves. Hasara uses a razor blade. The valves are made of a hardened
material so if you're careful, you're not going to hurt them. You
can also use a wire brush to clean the valves.
4. "I pretty much stay away from the
slot where the valve goes in," Hasara said. "If you think you
need to clean the slot itself, don't do anything that would allow
foreign objects to fall down into the cylinder." Hasara suggests if
you do try to clean the slot, maybe put a shop towel on a screwdriver
and gently wipe it out. Don't scrape the slot.
5. Repeat the process for both exhaust
6. Put the exhaust valve housing back
into place. Before replacing the bolts that hold the exhaust valves
into place, put a drop or two of Loctite on the bolts. Tighten the
Adjust the chain tension on the
Although Hasara said, "It's a good
idea to check the chain tension on your Polaris anytime you check the
power valves," it's not a bad idea to check the chain tension on
your mountain sled regardless of the brand and model. "The chain
can stretch on any snowmobile, not just Polaris," he said.
We'll cover how to check the chain
tension on an RMK but be aware that the exact method of checking
other brands might vary a bit.
1. Remove the side panel on the
chaincase side of the sled.
2. Remove the exhaust can. This is a
must so you have access to the chaincase.
3. On the front of the chaincase-toward
the front of the sled-find the jam nut.
4. Using a 9/16-inch wrench, hold the
bolt and loosen the jam nut two or three rotations.
5. Then, using your hand and not a
wrench, tighten the bolt until it's finger tight. If it won't
turn, then your chain is already tight. Back the bolt out and
retighten with your fingers.
6. Retighten the jam nut.
7. Replace the exhaust can.
Hasara said there was a consensus among
several of his mechanic friends who work on Ski-Doo sleds that one
of-if not the-most important maintenance course of action is to
clean the primary clutch on a regular basis.
Hasara explained, "The reason a
Ski-Doo clutch needs to be cleaned more often is because it's more
enclosed compared to say a Cat or Polaris. So the debris tends to
stay in the clutch area rather than fall or blow out. That debris is
mostly belt dust."
In addition to basic hand tools, to
tackle this job you'll also need a clutch puller (an online check
at www.parts-unlimited.com shows a Ski-Doo clutch puller for around
$20) to take the clutch apart.
If you're not comfortable tackling
this project, at least power wash the clutch, Hasara said.
You don't have to remove the belt
before washing out the clutch. Go to the car wash after each ride.
Use soapy water first, then clean water. Stick the wand right in the
clutch. When you're done power washing the clutch, fire up the sled
and let it run for a minute or two and the water will disperse. If
you can't power wash after every ride, Hasara said do it at least
every 500 miles. The same goes with taking the clutch apart and
cleaning: every 500 miles.
If you're going to remove the clutch
to clean and inspect it, here are the basic instructions.
1. Using 21mm wrench, remove the clutch
2. Using the clutch puller, remove the
clutch as a complete assembly.
3. Use the clutch puller to separate
the clutch halves. Separate the governor cup from the movable sheave.
4. Inspect the bushings on the arms and
the rollers. Replace if worn or damaged.
5. This shows the belt dust that was
left after tapping the clutch on the bench. The clutch hasn't even
been cleaned yet.
6. Clean the clutch with hot soapy
water and a brush. Rinse with clean water.
7. Reverse the process to put the
clutch back together and back on the snowmobile.