400EX smokes what to do

[SPLDan]

I'm thinking about pickin up this 400EX that smokes a little bit and just figureed I should clear up a few thigns before and get some input ..

It somes a lil on start-up and has a steady stream once its warmed up and your on it .. Its not to bad but enough to notice it .

I was going to do a .40 over 11:1 Weisco piston , bore and hone it and a new topend gasket set with a cometic HG ...

What about a cam will this be a good time to do it or should I wait it out ?

Quad is only gonna run on 100 Octane Sunoco GT Fuel so I dont think detonation wil be a problem

I figure this will run me around 250 $'s and some downtime on the quad probally a weekend at most .

Do the 416cc quads pull much harder than a regular 400EX . I'm not gonna put no rev box on it and it has a Full HMF Exhuast and Jet Kit already .

[Chevy1500z71]

it will be definitly beter with a 416...

[kfx400rob]

get a z

[Chevy1500z71]

get a ltr

[Yamaha72]

It smokes because the rings are shot, so yes putting a new piston in is not a bad idea at all... The JE piston will run you 150-175, the bore will run you from 60-80 depending where you go, so your guesses where pretty accurate, but the JE pistons do require the cutting of your rings to custom fit them. Detonation will not be a problem, you could run a little hotter plug, and for the cam, you don't need it unless you want that extra power, but a cam will run you 160-190 depending on which brand and that is with your core exchange...

[Chuck_Norris]

with 11:1 you would still be OK for 93 octane.