Over the fall I rebuilt the top end on the 400EX. Heres a list of things that was done or replaced...

416cc 12:1 High compression piston by CP piston
Stage 2 Hot cam
Lexx Slip on muffler
Uni Air Filter
Carb Choke delete
Cometic Gasket kit
New Head pipe gaskets
Stock Head studs

The slow jet is one bigger than stock, but I would go maybe 2 bigger than stock. Forgot what the main jet is, I think its a 168.

I bought an OEM cylinder off Ebay and sent that one out for machine work. I bead blasted the head pipe, cylinder, cylinder head and cover. Rebuilt the carb with new OEM float valve and jets.

The quad runs different now. It revs quicker, pulls harder and goes faster. I took my time building this and had no problems. If I was to do this for somebody else I could never get what I would want for payment. IMO, want it done right do it yourself, or just leave it stock and save your money. I just put new tires on this quad. That alone made a big difference. 2nd gear and the quad will pull the front tires off the ground. I been running 93 octane with stabil mixed and some Lucas fuel additive to lube the cylinder a little bit more, probably doesn't need it though.

I will post pictures, riding vids and sound files when I get a chance stay tuned.....

 

Nice i wish i culd do that with my lt230e i just dont have the $... and im sorta lazy

 

Before summer I would like to install a CFM oil tank. It holds 1.25 quarts more than the stock one. Anyone have one of these? If so how are they?