Can-Am Motorcycles by Bombardier

Can-Am Tech Tips

Classic CanAm

Technical Tips & Fixes
Take what you can use and leave the rest
Updated 3/2/01

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Special thanks to Dan Barnhill for cutaway Sonic photos
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Most of these topics came from email questions I've received from viewers. There is a great deal of assorted information in this section. I realize that it could be better organized but we constantly come across tidbits of useful information requiring frequent updates. Please take some time to scan this section for a solution to your problem. It just might be here.
(Click on topic)
Aligning TNT Rotary Valves
Aligning MX Rotary Valves
Petcock Fixes
Clutch Slippage
Clutch Drag or Stiffness
Clutch Cover Leaks
Removing the "Sponge" from the Oil Injection Reservoir
Broken Kickstarter Hubs
I changed my transmission oil. Now my kickstarter makes a ratcheting sound when the engine is running.
Broken Countershaft and Chain Guard
Removing the Oil Injection System
Intermittent Richening of Bing Carb
TNT Battery Fix

Rotary Valve Alignment -- TNT & Qualifier (symmetrical valve)
The symmetrical rotary valves can be installed either way. You can't put them in backwards. But you can misalign them. Make sure the piston is locked at TDC with a long 8mm bolt that has been ground to a blunt point on the end (or if you have the special tool, that works!). Don't just "eyball" it -- unless your name is "Lucky." The locking bolt goes in the crankcase drain hole in the front part of the engine cases (directly below the exhaust port on the cylinder).
This Tech Tip suggested by Pete Snell

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Rotary Valve Alignment -- MX Models (Asymmetrical)
Same procedure as above, just goes in a different location. These valves can be accidentally installed backwards. So be careful!

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Leaky Petcocks
Early model petcocks: Anybody who owns an old TnT or MX-1 through MX-2 has probably experienced the frustration of leaky petcocks common to the 3 position fuel valve. A new fuel valve, if you can find one, is anywhere from $25 -- $35 and will eventually leak. There are two potential fixes to this problem. The first is the economical approach Suzuki has a petcock that is very similar to the Bombardier unit, and sells the gaskets for about $12. They fit the Bombardier petcock perfectly. These are common Suzuki items so your local dealer will probably have them in stock -- Suzuki Part Numbers 44341-05110 and 44300-28817. You need both items. Tech Tip submitted by Ed Tobin

The second way to eliminate the problem is to use the 2 position valve found on the MX-3. It costs more than a gasket kit, but the valve is designed better. If you're racing vintage motocross you don't need a reserve anyway. Tech Tip submitted by Fred Brown

1979 to 1981 Petcock Grommets
The later model CanAm's (orange tank) use a push in petcock. These valves don't usually leak but the rubber grommet that holds them in can get hard from age and crack. Ed (Mr. Fixit) Tobin had this problem and found that the petcock grommets are still available from Sea Doo dealers. Just ask for Sea Doo PN# 570-1351-00. Way to go Ed!

Clutch Slippage
Lots of people write to me about clutch slippage problems on the 2 strokes. The most common source of this frustration is the oil you are using. CanAm owner's manuals say that you should run ATF or multi viscosity oil in the transmission. WRONG! Most of the time, switching to straight 30w motor oil or light 80 weight motorcycle gearbox oil will fix the problem immediately. If you're riding in very cold weather the clutch might drag just a bit when the engine is cold, but you can live with it for a few minutes until the motor gets hot.

Clutch Drag or Stiffness
This is usually the result of a worn clutch basket. Remove the clutch assembly and look at the fingers on the clutch basket. The plates have a tendency to make indentations or grooves on the fingers. Carefully file these areas smooth. Make sure that you remove the same amount of metal on each finger so the force of the engine is evenly distributed to the protrusions of the clutch plates. If the fingers are too worn, or the indentations are too deep, you should replace the basket.

Clutch Cover Leaks
You don't have to look too hard. It's leaking at the kickstarter seal and/or where the left side engine cover (clutch cover) mates to the center cases right behind the kickstarter. The later model CanAm's (around MX-4 and up) have an additional screw hole cast in the cover to the rear of the kickstarter which helps, but sometimes they leak too. There is no gasket on the clutch cover. I found that GE or Permatex hi-temp silicone makes a good gasket substitute. I use the blue silicone but any color works fine and you won't see it anyway.

First, you will want to replace the kickstarter seal in the cover. Do this even if it's not leaking yet. You can take the old seal to a bearing house to have it matched up, or better yet, just order one from Tony Murphy Rotax or any of the other suppliers I have listed in the parts sources section. They are only about $5 and this is the best time to replace it. Make sure you grease up the seal before putting the cover back on.

Clean the matting surface on the engine and clutch cover with brake cleaner or acetone. If your CanAm has oil injection be careful not to lose the small o-rings that connect the oil galleys between the cases. Apply a small bead of silicone around the entire clutch cover sealing surface, taking care not to get too much around the oil galley near the bottom of the cover. If you apply too much goop it will squish into the oil galley and block lubrication to the main bearing. Re-install the cover and tighten the screws. The silicon will squish out and look goofy but don't worry. After it dries just grab one end and peel off the excess. Let the silicon set-up for about 24 hours before putting oil in the gearbox.

Removing the "Sponge" from the Oil Injection Reservoir
This is a big job, but becomes necessary as your CanAm gets up there in age. Early CanAm's have a large sponge baffle in the oil reservoir (frame backbone) to help keep the oil near the feed line fitting at the rear of the backbone. This foam baffle is roughly 1.5" X 1.5" by about 1 foot long and is totally unnecessary if you keep the oil reservoir reasonably full. CanAm sent out a service bulletin on the very early models notifying owners that these baffles have a tendency to deteriorate and plug up the injection system. They made a replacement out of more durable material, but even the newer baffle has a tendency to come apart over the years. Some people simply don't trust oil injection anyway and switch to premixing. You will hear a variety of opinions from people about removing the Rotax/Mikuni oil injection system. But my experience is that the system will offer far more resistance to engine wear and should be left intact. Oil pumps and parts are cheap to replace if you doubt the longevity or condition of the one on your bike.

Here's a tip on removing the baffle from Al Roberts in Texas

I drain the oil then I take the bike to a car wash. With the "bolt" out of the bottom, put the wand in the top with the setting on soap and spray. The soap takes the oil out and the water pressure breaks whatever is left of the sponge into pieces which come out the hole in the bottom and the fill hole in the top. I keep the wand in the top hole until I see no more sponge. I then put the setting on rinse and continue until the water coming out of the bottom hole is clear. To be sure that all of the sponge is out of the tube, I "blow the tube out" with my air-compressor. This also gets out any water that is left. I then, to make sure, use my shop-vac. This is very thorough and the tube is clean. I have used this method on four bikes so far and it works great. If you are restoring a bike and it is going to be a little while before you are ready to put oil back in the tube, put a 10mm bolt in the bottom and fill the tube with transmission fluid. This will keep the inside of the tube from rusting. When it comes time to put the bike back together, the thin fluid drains easily, and any left will mix OK with 2-cycle oil and burn.

Another Baffling tip from "Scott"

Hi Mike I have a tip on the oil reservoir baffle. On many of the bikes I have worked on the baffle is still intact. In this instance I find drilling a small hole (3/16) in the back of the reservoir is the best fix. This allows you to push the foam out in one chunk. Rinse the reservoir out to make sure you got it all and weld up the hole and grind down the weld. I've done this on several restorations and it is not noticeable after paint. Great site you've got I use it everyday.

Scott - posted 3/4/2006

Broken Kickstarter Hubs
Did you think you were going to read some kind of magical solution? Yeah right. This is the most common problem CanAm owners experience. The best prevention is simply to make sure the K/S hub bolt is tight before each ride. The K/S shaft is hollow and encompasses the shift shaft. If you find yourself replacing a broken K/S lever hub with a new one, check to make sure that the K/S shaft has not become elongated before you install it. If the shaft is out of round and you don't repair it, you will end up right where you started in a short period of time.

Here's a kickstarter tip from Paul Kalika in Austrailia:

I've found that when the kickstarter pivot is a bit worn, any grit causes it to jam, usually at an inconvenient time. I've started slipping a cut length of a BMX inner tube down the kickstart lever and stretched over the knuckle, with a cable tie closing off the loose upper end of the sleeve. Since I've been doing this, I've had no drama's and as the lever pivots smoothly the shaft spline is getting an easier time of it too. Simple and cheap.

I changed my transmission oil. Now my kickstarter makes a ratcheting sound when the engine is running.

Did you use a 17mm wrench to change the oil? Did you also hear a snapping sound when you took the bolt out? You doofus! You took out the kickstarter retaining bolt (don't feel too bad, lots of people email me about this problem). I've heard rumors that you can remove the bolt again and rewind the kickstarter spring without taking the motor apart, but I've never done it. Probably because I know the difference between a 17mm socket and a 6mm allen wrench.

Here's a letter from a viewer that might help you out:
I have experienced the tell-tale "zing!" as the wrong bolt is removed from the bottom of of a Rotax motor. On my 1980 MX6 125, I did this and quickly realized I just made a big mistake that my foggy brain remembered so long ago with an old TnT I had. Just push the kickstart lever ALL the way down and re-install the bolt...if you have a good start-spring, the gear just needs to be rotated about 180 degrees and re-install the worked for me! -- Mike Hartney

You can thank Mike Hartley for saving you a ton of work if this happened to you!

If that doesn't work
Click here to view kickstart preload instructions from shop manual 100kb

Broken Countershaft and Chain Guard
Broken countershafts are most common to the 250 MX-4, 5, 6, and Qualifiers. You suddenly stop moving and see that your chain is off the sprocket. Then you notice that there is no countershaft sprocket! Time to spend some money on a shaft and split the cases. Not much fun. The best way to prevent this is to make sure the chain is adjusted properly. There should be almost 2" of play.

Another CanAm engineering marvel is the horseshoe shaped chain guard that surrounds the countershaft sprocket. Take it off. I'm sure it was invented by the same engineer that came up the foam sponge in the oil reservoir. It's supposed to protect the timing cover from damage in the event you throw a chain. I've never seen a damaged timing cover, but I've seen a number of broken countershafts and cracked engine cases as the result of a thrown chain getting jammed between the sprocket and the guard. Even if you throw a chain and somehow end up breaking a timing cover, it's much less expensive than engine cases or a countershaft -- and it's much easier to fix.

Removing the Oil Injection System
Although I personally like the Rotax oil injection system, many people write and ask how to remove it. The advantages of pre-mixing are less weight, reduced risk of engine seizure due to malfunction, and simplicity. But my experience with the oiling system is that it's reliable (with proper care) and greatly sustains engine life. Because Rotax engine parts are so expensive and becoming less plentiful I'll take the gamble of pump failure against premature motor wear any day. I realize that this is a personal preference and have decided to give a brief synopsis describing the procedure of oil pump removal for those of you who prefer the standardized method of lubrication. I do this because I hear many people tell me that they've decided to do away with the oil pump and simply started pre-mixing. This is a WAY bad idea if you are working with a Rotax motor designed for oil injection.

Rotax engineers were smart people. They borrowed the automatic lubrication system idea from the Bombardier snowmobile motors (the largest manufacturer fo snowmobiles and watercraft in the world). Although there are a few areas that could have stood a little extra thought (such as the routing of the clutch cable) the engine is built to be run as designed. The right side of the crankshaft utilizes an "oil slinger" to insure proper lubrication of the main bearing. The slinger is a large washer with a nipple that fits into the crank. It takes the oil from the galley and forces it into the bearing. The flip side is that it acts as a barrier if you decide to premix. What happens when you eliminate the oil pump without proper engine modification is that the right side main bearing will prematurely wear from oil starvation. If it seizes and spins, you bought yourself a new set of engine cases. If it wears and gets sloppy you will find that the flywheel starts to hit the ignition stator during operation and destroys the stator (along with the flywheel). There should be NO detectable play in the right side engine bearing.

To do the job right requires complete disassembly of the engine. You must remove the right side main bearing from the crank to access the slinger. Then you need to fabricate a spacer of the exact same thickness but of smaller outside diameter (would look like a big washer). This allows oil to get between the crank half and the bearing. But to provide the premixed fuel a path, a 1/8" hole has to be drilled in the right side transfer port of the cases (there are bulletins from the factory on this procedure which I will try to make available in the future). However, you can see how the hole is positioned by looking at the left side transfer port which most engines have from the factory. The last thing necessary is to make a small plate to cover the hole in the clutch cover where the oil pump used to be located to prevent loss of transmission fluid. You can seal the plate to the cover with a good sealant such as Permatex or Locktite 505.

Our Classic CanAm racing team uses both methods of lubrication on our 4 motorcycles. Fred Brown prefers premix, and I run the oil pump on the bikes I maintain for Jim Atkins. The MX-2 bikes used a lock tab instead of a split cable, which is how Jim's bikes are setup. When you use a split cable the pump is regulated by both throttle position and engine RPM. But the lock tab eliminates the need for a split cable and holds the requlator about 3/4 full on. The biggest disadvantage to this setup is that Jim's bikes will smoke like a chimney from excess lubrication when he has to sit at the starting line for more than about 60 seconds. I hadn't noticed this until watching some home videos of various races and now instruct Jim to wait until the last minute before starting the bike to minimize this problem. Although the delay makes him a bit nervous, our CanAms always start within one or two kicks. But to substantiate my position, I recently inspected the top end off Jim's 125 and found virtually no signs of wear after 20 motos and two 45 minute GP races. This is due not only to the forced lubrication but also the modern synthetic oils (we run Castrol full synthetic 2 cycle oil).

As I stated earlier, the best method of lubrication is highly subjective. It's important that CanAm owners utilize whichever method makes them most comfortable. But please make sure to do it right.

Intermittent Richening of Bing Carb
With vintage bikes you will run into problems that wouldn't normally occur in the lifespan of the motorcycle. The reason being that the parts have usually outlived their life expectency and normal troubleshooting techniques don't always apply. Rubber, plastic, and metal react to age in funny ways.

This section applies to the Bing carbs with a "choke lever." I ran into a problem with our vintage race bikes that baffled me for some time. On the 125 I'd get the jetting dialed in perfectly and then for no apparent reason the bike would run extremely rich the next time we started it. This was very frustrating because I'd dial it in at home and the morning of the race it would suddenly start to load up and run rich. Well meaning people would come by and tell me I needed to rejet. But a jet doesn't change it's properties overnight, and neither does the density of air at the same altitude.

I initally figured it to be the float needle, although it showed now signs of wear under magnification. But then I noticed that the plunger (the piston that goes inside the carb and attaches to the choke lever) had a rubber insert in the bottom. This piece on our carb showed very slight signs of wear under magnification. I called Bing International and the technician immediately told me to order a new plunger ($12) and the problem was solved. When I would turn on the choke (actually a richening device) to start the cold motor, the aged rubber didn't always seal completely when I turned it back off.

TNT Battery Fix Submitted by Ed Tobin
My TNT (pictured in Viewer's Pictures) had sat in the shed for a couple of years unused except for an occassional start-up to keep the carb from gumming up. This summer I dusted it off and started to ride it again. While it sat idle, the battery had gone bad. Instead of replacing it with
another led acid battery, I hooked up a gell cell off of the Baja Designs kit on my modern dual sport bike and it works just fine. I also had a problem with the flasher device that blinks the turn signals and so I tried my Baja Designs blinker unit. It connected right up and worked just great

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