Hey everyone new here. I have a ds 650x stock other then I have air box lid off and running half 91 and half avgas. Looking for performance mods. I just bought some new front all ballz bearings and a stage 3 AMR rev box. Just wanna know what works for everyone else and when I need to start rejeting. I ride dirt and sand from Oklahoma. Thanks everyone for the help.

 

If stock then why the 91 octane and especially the AVgas?
Give the OMR stock carb mods a try, you will be impressed. Need an open end cap or some sort of exhaust to really get some gains. Gearing goes a long way also.
Tons of threads on here for mild to wild mods and builds. Big Gun CDIs will give you the least amount of trouble for the affordable boxes. Vortex all the way if you are going with a 730 or bigger in the future.

 

That's what my buddy runs in his bikes so figured it would be okay to run that fuel in mine. I got a stage 3 AMR cdi box and just bought a new open exhaust tip I also run open air box too. Does that carb mod work real good with open air box? Still need to get jet kit and k&n air filter. Still running stock. The new cdi box made a huge difference.

 

I will just say you will not be disappointed if you do the stock carb mods. Further proof is that I could never get the front end off of the ground until I did the mod. I ran no air box at all, just K&N with an Outerwears, and the mod worked wonders.
I'd definitely give the lower octane (cheaper!) fuel a try. See if you run any hotter than you're used to, if not you're good.

 

I will give it a try the 2006 are easy to get front end up. I will try the mod. I also changed to the ice coolant to keep the engine cool works great. Just gotta empty out the regular coolant first. I gotta find the k&n with outerwear togather in a package deal because the are high. After we did the cdi box change my buddy that has other bikes says mine is now faster then his. He has two yfz 450s one is a 450r se fuel injected and has a tri-z.

 

I agree with Ace, no need running anything higher then 91 octane unless you have internal engine mods. Your just wasting cash that can be put towards your other mods.