11:1 piston in 400ex

[camden_bmx13]

I was wondering how much of power improvements the 11:1 std bore piston will give?
what jetting is recommended with it?

[drew416ex]

you will notice some gain over stock, but not much without a cam. You will notice an all around difference, but most of it will be low do mid range. As far as jetting probably between a 155-165 and 42 pilot.

[camden_bmx13]

I've also heard about problems of blowing head gaskets with the 11:1 piston.
Is that true or is just a shotty gasket?

[drew416ex]

I never had a problem with 11:1. I think the main problem most people have is over tightening the head which causes the threads to pull and the gasket to blow. If you ever go over 11:1 though, you may want to think about hd studs.