First post, hi to everyone I'm david.

I have a lot of questions for anyone who feels they can answer them. I bought a sled while I lived in Colorado for $200. It was a beat up '96 or maybe '97 500cc Summit Ski-Doo. The motor ran strong after we beat up the suspension, brakes, skis etc.

So I moved back to where I'm from (in maryland) and brought the engine from the sled with me.

So my questions are..

I didn't have room for the exhaust pipe, is there any pipe I could use to replace it. Perhaps an old motorcycle exhaust from a similar sized engine?

And since the sled was operating at 10,000+ ft. and now I'm at about sea level, I'm assuming I need to re-jet the carb? How do I know what size jets to put in?

Also, I have the engine all assembled and can't seem to get it to fire? It back fires out of the manifold, but doesn't keep running, maybe not enough back pressure?

any way thanks for reading my ramble and thanks for the help

You should attempt to find the correct pipe. The pipe is "tuned" to that engine, both in length to the restriction and to volume of the pipe. It's an important part of the system, when the piston is at bottom dead center in a 2-stroke, both the exhaust ports and the intake ports are open and a certain amount of fresh fuel/air starts to travel out the exhaust. When the fuel/air is ignited, there is a pressure wave that occurs, which rebounds off the restriction in the exhaust and pushes the fresh fuel/air that has tried to escape back INTO the cylinder. Using the wrong pipe will result in power loss and a lean condition which may create a hot condition that can melt pistons.

You are right about the jetting. You will be jetted VERY lean if you try to run the sled at sea level. Find a jetting chart for that engine and jet accordingly for elevation and temperature. Lean = HOT = melted pistons. Same as above.

Welcome to the forum!

Thanks for the quick response dude...

where's the best place to look for the pipe? and where could i find a jetting chart do you think??

Also, am I going to be able to run the engine at 80 degrees? Will I need a new radiator?

Any dealer should have a jetting chart. The chart is also in the owner's manual, if you can find someone with a similar sled, they can help too.

Some of the snowmobile salvage yards should have a pipe, I have used Al's Snowmobile Warehouse for odds and ends and had great success. You can also put a "wanted" in the forums, some are more active than this one, and may have more visits. Someone may have one sitting around in their garage after they added twin pipes or something.

What are you putting the engine in? Liquid cooled snowmoblies cool the engine by throwing snow onto heat exchangers in and around the tunnel. Without snow to hit the exchangers, the engine can overheat pretty quickly. Guys that do grass drags will run the sled down the course and then hook it up to cooling water to keep it from overheating. Others that have modified the engine to run in go-carts or dune buggys have to add a fan-cooled radiator system to get the engine cool. If you're doing something other than a sled, you will have to get creative to keep it cool.

Good luck!

The engine is going into a go kart. How about an over sized radiator that is getting solid air flow?

A radiator without a fan will work ok if you are moving, but it may be lacking when airflow is minimized at slow speeds or stopped. I would install a temp gauge to see the temps rising if the radiator doesn't have a fan... and make it easy to modify so if you go too small you can change it out without a ton of work ;)

I'd buy the engine from you, but its going into a go-kart so nevermind