IDK your elevation, but I'm running without an airbox, UNI filter, modified end cap on a stock muffler, and the OMR carb mods. At about 1,300 feet elevation, my DS runs great with a 175 main jet. 185 jet with a stock airbox and questionable muffler just doesn't sound right in your case.

Tractor muffler could be the culprit. Putting a stock muffler back on with a different endcap can be an affordable alternative to an aftermarket muffler. I did some searching in this forum as well as others that cater to the DS650 last year, and found some threads that support buying an aftermarket end cap that replaces the two turndowns of the stock end cap with a single open pipe can produce more hp and sound better/louder. Some even had dyno results to back it up. I could be wrong but I think it was even THE STIR that had an excellent thread where he documented dyno results of the stock endcap, and multiple fabricated end caps and compared the results.

I wanted to go cheap. I wanted to keep the stock end cap with it's spark arrestor, but cut off and replace the two down tubes with something that would flow better. I went looking on fleabay for a end cap for aftermarket mufflers that would fit on the stock end cap after cutting the tubes off. I got lucky and only spent about $20 for a titanium FMF end cap, and stainless rivets to mod mine. The butt dyno tells me it's running better, and the sound is more aggressive and deserving of the 650 engine. Here is my thread if you want to check it out. http://forums.atvconnection.com/can-...d-cap-mod.html

 

Thank you for all advice. I will start to source out a new muffler once I have some money available. I am in canada, and the cheapest stock muffler I can find anywhere online or locally is ballpark 200 bucks, and any aftermarket FMF etc is running almost 300 or more. My current setup works, just not very well.

One mention was that my main jet may be a little large, what would be the effects of that? I will check my plugs for color, but is there anything I would notice while driving? I assume if I was to put on a good pipe that 180 or 185 should be fine, as outlined in the Dynojet recommendations.

Thanks

 

$200 for a stock pipe? have you made a post here looking for a pipe ? Ive seen them given away for FREE ....

 

Hey, ya that what I have seen everywhere I have looked, I thought it was pretty steep too. I haven't tried here yet just because I assumed most of the guys are from south of the border, and shipping such an item would be pretty dear. Maybe worth a try...

 

You can also look over at nomercyracingdotorg. There is alot of DS people over there.

 

I little looking .... beat this deal .. thank me very much

CAN-AM DS 650 DS650 PARTS

 

I'm pretty late here I'm sure you don't have the DS650 anymore. I own a 2001 DS650 I was looking in to buying a new muffler for it. Before I did I did a lot of research and learned the following. Bombardier installed all pre tuned mufflers for their DS650 quads. Welding a tractor muffler on is a bad idea on any terms. You can buy a performance muffler but if it's not tuned appropriately you're gonna cause more damage than good. You may say an increase with a performance muffler but it needs
to be tuned to the engine. That's how finicky these engines are. I read a lot and watched a lot about Rotax ATV engines before I did anything to mine. Please don't take what I'm saying as anything negative I'm just trying to help you understand why it's bad to just mix match parts. The tractor muffler is more than likely your culprit! I would definitely get a stock muffler if you still have the quad. The stock muffler in my opinion already sounds pretty good.