Bigger Sleeve

[Chino886]

If I change the sleeve in my 02 400EX to possible a 416, which I believe is still stock bore, am I going to have to get a new piston, or do pistons go by bore size? I think I am going to have to get a new piston.

Thanks,
D

[jak1389]

well a 416 is not a stock bore. if you meant will you have to re sleeve it, then no. and you will have to up the piston size. the 416 bore is 87mm, so the piston will also have to be 87mm.

[greg_gorrell]

im not trying to jack your thread or anything but while we are on the topis does anyone know the id of the cylinder on the 02, without the sleeve?

[Chino886]

Is the 406 a stock bore? Will that work with the standard bore piston?

[jak1389]

a 406 is not a stock bore either. the stock bore is 85mm and you will be incresing it to 86mm.

[400exrider707]

Originally posted by Chino886
Is the 406 a stock bore? Will that work with the standard bore piston?

Right on the side of your engine it is stamped 397cc's. That is stock and it is an 85mm piston. If you want the 416, you need to have the cylinder bored .080 over and buy a piston accordingly. It will be the 87mm piston like jakl389 stated.