440 kits

[mar400ex]

how hard is it to re-sleeve a 400ex for a 440 kit? what all do you have to do?

[440ex2001]

you need to take it to a shop. They will have to bore out your clylinder for the 89mm sleeve to fit in then they may have to bore out the sleeve alittle or atleast hone it for your new piston

[tator]

Prettty hard take it to a bike shop that you trust.:p

[devildriver422]

o/t but does anyone know how high u can bore out a 400ex and still be able to use pump gas?

[AC 400 ex 02]

do u mean pump gas?

[devildriver422]

yea my bad i was gonna say n still use pump gas then i decided to say n not use race gas...kinda got mixed but i fixed it

[cletusEX]

The compression is what makes you have to use race gas.

[devildriver422]

o well then how high of compression can u go

[TC426EX]

If you wanna run pump gas then 11:1 is absolutely the highest you can go. If you dont mind running race gas then 12:1 is the highest safe compression. If you wanna start going 12.5:1 or 13.5:1 or something you will need to get a heavy duty rod put in like the carillo or sparks. Keep in mind that the higher the compression, if something blows in the motor, its gonna blow big time!!

[devildriver422]

wuts the stock compression on a 400ex and does does the stock changed to like 10.5 make much of a difference?

[440ex2001]

its 9 or 9.5 to 1

[devildriver422]

would changing that to 10.5:1 make much of a difference?

[440ex2001]

not much

[cals400ex]

stock compression is 9.1:1. going with 10.5:1 will make a difference. i think the cam will make more of a difference than the piston itself, so get a cam while your at it. my buddy put in a 10:1 406 and a hotcam and it made a big difference. we do a lot of drag racing and i haven't seen him get beat by a piped z or kfx yet.