1970 Ski-Doo Olympique 12/3
Angie and I found this sled on eBay. In retrospect the $300 I paid was way
too much, but based on the story the seller gave I assumed any problems
would be an easy fix.
The first fix was very easy. A previous owner had put the carb together wrong, omitting two gaskets, plus the float needle was stuck closed. The carb to engine gaskets were missing and the spacer was on upside down and backward. Once the carb was straightened out the little 299cc fired up and ran strong. Until a slight navigational error had Angie, myself and the sled on our side laughing like fools. Unfortunately this stirred up the crud in the gas tank and that crud made its way up into the carb and engine. The engine would idle but go no faster.
During the summer of 2002 I set to making this sled run right. I took the
engine off the body and rebuilt it with NOS rings and Kimpex seals and gaskets.
The cylinder got a light honing as it was well within spec. The suspension
was cleaned and lubed.
I flushed the gas tank with copious amounts of water and vinegar to break up 30+ years of varnish and rust buildup. Early experiments showed that flushing with gasoline was dangerous and not very productive. I chose vinegar because its cheap and has mild acidic properties. In retrospect I needed to introduce something like a piece of chain into the tank for better mechanical breaking action. Just using vinegar is a serious PITA! It got it clean finally but took nearly 2 months..
Once the tank was relatively clean I used POR-15 gas tank sealer to seal the tank. This is one product I can definately vouch for. Use it per the instructions and it will do what it says. During the winter of 2002/2003 I rode this sled alot and never had a bit of trouble with the engine or fuel system.
in the winter of 2002/2003 I noticed a slipping feeling when riding the
sled. This turned out to be "ratcheting" which is the drive cogs
losing they're grip on the track and spining. I fixed this by replacing
the cogs which is a relatively easy task. New drive cogs were available
through my local sledshop.
Late in that winter I replaced the throttle cable. This is one project I wish I'd done before the snow flew. I had always just sort of assumed a sore thumb was a normal by product of riding a snowmobile. Friends it just isn't so! I bought a universal throttle cable from Parts Unlimited and cut off one end to fit my sled's Tillotson carb. The other end slips into the throttle lever. In 15 minutes of work I reduced the throttle pressure needed 300%, the difference is amazing!
In early 2004 I got a new seat cover made by A-1 Upholstery & Repair in Michigan. Diane and her folks did a great job. I unfortnately didn't get the seat on and frankly didn't have any time for the sled until last summer. Which is when I found that reusing the wooden seatbottom is a lousy idea. I ended up fiberglassing the seatbottom so the hooks that hold it to the sled wouldn't rip through the wood. I need to replace the hooks yet, but I also need a new track and I figure to do both at the same time.
To get the sled ready to ride for the 2004/2005 season I had to again rebuild the carb. It looked like water had gotten in. One welch plug was pushed out and there was some rusty crud. These old metal tanked Ski-Doos are prone to condensation if you don't ride them much and I didn't get to ride much during 2003/2004. I have gotten really good at rebuilding the old Tillotson carbs though. I've written a tech article on it, click here to check it out.
The top picture is from the New Hampshire Snowmobile Museum winter 2003 show. That show this was the only sled I owned that actually ran. So my wife Angie and I rode it together all day. The best part were the wild looks people gave us while we putted around on the sled. When I was a kid we always rode 2up on sleds because there weren't any extra machines to go around. Now I've got lots of running sleds but its always fun to take a ride 2up on the Olympique. Guys, if you've never let your wife drive one of your old sleds get out and try it. I like letting Angie drive because it gives me a chance to take in the scenery and relax. Plus when I had the heavy throttle problem it was her thrumb that got tired. She likes to drive so she'd never admit her thumb hurt!
What do you think about this story? Let