bombardier DS 50

[my05z400]

My son has a 2003 DS 50. Looks just like a DS 90 except has a 50 2 stroke automatic trans. Runs fine for about 15-20 mins then has not power. Put new gas and replaced spark plug still does it. Would the CDI cause this problem?

[EthansDad]

What do you mean no power? Like it won't pull itself, or the motor is cutting/dieing? Does it still rev up with the wheels off the ground?

[my05z400]

Yes no power will not pull itself. With the rear tires of the ground runs better.

[EthansDad]

my best guess given the age of the bike and that its a 2-stroke cvt, the torque spring has given out. when they get old and heat up, then fade out. let it cool for a bit, will run again just a little, then start bogging and not able to pull itself.

what's happening is your CVT transmission is shifting into a higher gear too soon because the torque spring that is designed to hold it down into the lower gears has failed.

find out what type torque spring it uses and replace it, then let us know how it runs.

-EA

[my05z400]

Thanks for the info EA. That sounds like a project that might be over my head. It is a hard repair? Is there anywhere I can get instructions for this? Someone I was talking to over the weekend said it could be a clogged exhaust.

[EthansDad]

I personally can replace the torque spring in 7 minutes - I timed myself one day. BUT, I've done a bunch of them so that's different. I think the average first time job is an hour, maybe 1.5. no special tools really, and the spring is a $20 part.

Check this video out. There are a bunch of folks on here that do CVT spring changes all the time, so if you do get into this, I'm sure you'll get the info you need if you get stuck.


IMO, a clogged exhaust would run crappy all the time, not just when it heats up. if the bike revs up great and sounds great with the wheels off the ground when its in a heated "state" that it won't pull, then I'd stick with my guess of torque spring.

-EA

http://www.youtube.com/watch?v=QR5JSq2VdYU

[chunky0071]

yes you could have a clogged exhaust screen take a close look at the very rear of the exhaust look for a bolt or allen screw that goes in from the bottom take out that screw and pull out the the screen there is no need to clean and reinstall just throw it away.

[my05z400]

took the screen out of the exhaust and cleaned the carb again runs like it should. Now I hope it keeps him happy until I can buy him a 90 quad for Christimas.