400ex-416ex rebuild [Archive]

WickedATVer

03-22-2006, 01:58 PM

I've torn apart my ex because at the end of the race season it was smoking pritty much all the time white smoke. The cylinder walls didn't look bad but, the whole valve head top of the piston and a little bit of the top of the cylinder was burnt and had a bunch of build up on it. I've already got a wiseco 88mm piston and I wanted to get oversized valves and titanium springs and retainers. Would I be able to gett away with using the stage 1 hotcam that was in it before and what kind of jetting should i be looking at?

stalefish_132

03-22-2006, 02:41 PM

Originally posted by WickedATVer
I've already got a wiseco 88mm piston

if i'm not mistaken to get a 416cc its 87mm piston and 88mm is 426cc:huh

hawaiiansupaman

03-22-2006, 03:23 PM

Originally posted by stalefish_132
if i'm not mistaken to get a 416cc its 87mm piston and 88mm is 426cc:huh

yes your right/ so you building a 426???

WickedATVer

03-22-2006, 03:50 PM

Ooops:ermm: I've been going by the 88mm for size thought 416 is what some one told me.

lafinrat

03-24-2006, 12:02 AM

Originally posted by WickedATVer
I've torn apart my ex because at the end of the race season it was smoking pritty much all the time white smoke. The cylinder walls didn't look bad but, the whole valve head top of the piston and a little bit of the top of the cylinder was burnt and had a bunch of build up on it. I've already got a wiseco 88mm piston and I wanted to get oversized valves and titanium springs and retainers. Would I be able to gett away with using the stage 1 hotcam that was in it before and what kind of jetting should i be looking at?

put stock size valves in it. spend the money on a smart port job and valve job. nobody makes ti springs for any atv. there are ti retainers though. the stg1 cam doesn't need any of that. stock would be fine.

jetting? what altitude?

WickedATVer

03-24-2006, 11:08 AM

With the jetting altitude isn't very much. I live in Maine I looked it up and the mean altitude is 600ft. Other things for the jetting I have the air box that hides the battery going get a K&N air filter, White Bros R4 exhaust and header. I planned on doing a port job along with it any way, still stick with the sotck vs. oversized?