Hello, I am a newcomer to your forum. I am not a mechanic but have a little experience in maintaining my bikes and a lot of experience riding mostly street bikes but grew up many years ago riding in the dirt. Because I may have trouble finding this site again, I would appreciate responses to be both posted on this page and to my private email nick.benson@verizon.net until I learn how to navigate this site.

We have a 2000 Can Am DS650 that we bought used. It has run great for eight months here in the mojave desert at 1800 ft elevation. After my daughter in law cleaned the air box and K&N filter (perhaps this was just coincidence) the bike has to be run with the choke half closed at all times to make it run decently. Added to this, my son put an HMF Competition exhaust on it before fixing the problem so now we have the issue of it needing the choke half on AND it bogs when quick throttling.

We took the carb apart and the main jet is a 175 (stock is 165 and mikuni recommends a 170 - remember it ran fine for 8 months). The pilot jet is a 45 (stock is 40).

These problems exist whether or not we take the air box lid off or leave it on.

We are also getting ready to put the new rev limiter on it, but want to wait until we get these other problems resolved.

Any help or ideas would surely be appreciated.

 

The motor is running lean; that is why using the choke (enricher) allows the motor to run better. Check for air & vacuum leaks; start at the airbox and the airbox connections to the carb.

 

I had that problem turned out i had a chunk of plastic the partially clogged the main jet in the carb...and i had vapor lock from the vent hose getting kinked.

i was thinking of putting that same pipe on my ds how do you like it, how loud is it compared to stock, and did you feel any power increase