I have an '05 DS650. I just finished my first weekend trip to the Or dunes. I installed a K&N air filter, rejetted, installed a CDI, and dropped a tooth on the front sprocket. While the low-end definitely improved, I still need more low-end. Any advice that you may have would be great.

Mutso

 

You said you just got back from the dunes, is it for hillclimbing that you need more grunt? If your not worried about drag racing drop one more tooth up front heck sprockets are cheap. What size tires are you running on the rear? Also if you swap to a 14t front there is a bolt that you will see that will rub the chain with the 14t, its an easy fix just flip the bolt around.

 

check out the link

http://www.hpresearch.net/

the end cap gives a huge boost for not much $

 

Try two teeth bigger on the rear sprocket too.