How hard is it to put in a 440 kit

[enduro400rider]

I wanna bore my 400 to a 440 how hard is it to do if i had all to machining done and i did the rest of the work. I have done soom work but not not a rebuild

[frogburner]

Well I can tell ya right now,, If you start builing a 440, dont be cheap, get the FDO Head studs, 3piece steel cometic gasket, For sure..

[44oEX]

it's not hard. it's just like a normal rebuild except that the piston is bigger.

[cals400ex]

same ol thing. just have the new sleeve installed in the cylinder. also, bore your case a bit to allow the larger sleeve to fit in with a bit of breathing room. you don't want a tight snug fit because that sleeve will expand when the bike gets hot.

[quadgod440ex]

i gotta question with this also after reading this thread ... when u said boring the case did u mean the bottom case where the crank is or were u just referring to do this to the cylinder because i have the 440 kit in the garage waiting to be put in am i missing something here with this boring ?? fill me in

[44oEX]

you don't have to bore the cases.

[cals400ex]

i am referring to the cases where the sleeve fits in when you install it. many say you don't need to bore the case. and you don't if your running a tapered sleeve. i have talked to a few engine builders and they all recommended at least cleaning up the edges of the case where the two halves come together. you can do what you want, i would never ever install a larger sleeve without at least checking these clearances. my tapered sleeve did fit in the case but it didn't have the proper clearance.