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 you ride.
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.
- Remove the secondary/driven so you can get to the gearcase.
- 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.
- 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.
- With the oil fill plug removed, pour the entire contents (6 oz.) of a bottle of ACT Flush Fluid into the gearcase.
- 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.
- Open the oil drain plug to drain the used fluid and flush fluid. Let the gearcase completely drain. Put the drain plug back in.
- 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 in.
- 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.
- 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 again.
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 eventually."
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:
- 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.
- 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.
- 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.
- "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.
- Repeat the process for both exhaust valves.
- 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 bolts.
Adjust the chain tension on the chaincase
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.
- Remove the side panel on the chaincase side of the sled.
- Remove the exhaust can. This is a must so you have access to the chaincase.
- On the front of the chaincase-toward the front of the sled-find the jam nut.
- Using a 9/16-inch wrench, hold the bolt and loosen the jam nut two or three rotations.
- 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.
- Retighten the jam nut.
- 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.
- Using 21mm wrench, remove the clutch bolt.
- Using the clutch puller, remove the clutch as a complete assembly.
- Use the clutch puller to separate the clutch halves. Separate the governor cup from the movable sheave.
- Inspect the bushings on the arms and the rollers. Replace if worn or damaged.
- This shows the belt dust that was left after tapping the clutch on the bench. The clutch hasn't even been cleaned yet.
- Clean the clutch with hot soapy water and a brush. Rinse with clean water.
- Reverse the process to put the clutch back together and back on the snowmobile.