what makes a 400ex a 416,426,440

[importracer_ky]

im looking to do some engine mods.i want to keep it reliable and trail ready.i have heard that the 440 big bore wears out a engine faster.whats the best engine mods to do to keep it reliable.

[tri5ron]

Originally posted by importracer_ky
i want to keep it reliable and trail ready. whats the best engine mods to do to keep it reliable.

fresh oil and filter.

Sorry, just couldn't resist.

[hypersnyper6947]

you can do a reliable 416 and still have enough power to keep up with stock 450s

[deathcorefan2]

yeah i was looking into a 416 also, i thought boring a quad diddnt do much for the power.

[powderider87]

Not much, Its the Higher compression piston you put in. pipe it, cam it, jet it, and 416 it if you want it.

[davidw2155]

Does anyone know how well the high compression, stock bore pistons work? I was thinking about boring to get high compression, but then I saw a high compression stock 85mm bore piston??? Any advantages to stock bore? Disadvantages?