Ok. Whats the scoop on mods for this? Most posts are getting to be a couple years old. I'm wondering what works. I have a k&n air filter, and Polaris / white bros muffler. Should I do the 800 header? fuel programmer? 800 primary clutch? or clutch kit? Timing key? What works? I dont mud ride. I ride mostly mid to high speed trails. I still want dependability but I just a bit more mid range snap....

 

by the sounds, you have already done the homework on what people are doing. back awhile ago the big thing was to put the air intake and header pipe on of the 800 becuase it breathed better and some noticed the power differnce. imo

 

I think the 800 head pipe and a fuel controller, and clutch springs, or a whole kit

 

I have a Power commander, 800 header, K&N filter, LRD Torc slip on, Heel clicker clutch kit. Cam and timing key comming soon.

 

I installed the 800 crank, balancer, 800 HO cam, JE hi comp pistons and had V&H do the head. With a LeoVince full system and Power Commander it was a 20% increase as measured on a Dynojet dyno. Also has EPI clutch kit. I raced a XP850 and up to 70mph he only had me a bit over a length so I was happy with that!

 

How much did all that work cost? Short of having a blown motor and needing a rebuild anyway it seems like it would have been cheaper to have just bought an 800. I'm not trying to knock you, I tend to do the same thing myself, its starts out with a few little mods and before you know it your over your head. I had a MXZ 700 that when i was done modding it it would run with 800's but its cost at least as much.

 

I bought the quad used for $2000 and on the first ride got smoked by a 800X2. Luckily I am in the industry and get all my parts for cost, V&H comped me the headwork so out of pocket was like a grand. Now I leave the X2 for dead!!!

 

Interesting now is the 20% measured at the rear wheel? Do you know the overall ratio of the 800 vs the 850 at the rear?

 

It was measured on a Dynojet chassis dyno, so yes, at the rear wheels. Unfortunately dyno numbers are somewhat irrelevant with a CVT style clutch which is why I stated % of increase. If you use the same tires and same clutching from one day to another you are fine but to compare two different machines doesn't tell you a whole lot.