Dome piston vs. flat top piston??

[GeoffM24]

I am putting in a new wiseco piston today and I noticed the Wiseco I just got is a dome piston while the ART piston I'm replacing is clearly flat.

I did some research and the 99 RM250 definatly came from the factory with a dome piston for "better combustion".

What the effect would the flat top piston had on the bike?

I'm ASSUMING it would have lowered the compression ratio?

 

[marcusgunby]

You cannot run a flat top piston in your bike unless you mod the head to suit.It will have low compression and not be optimised.

 

[GeoffM24]

Originally posted by marcusgunby
You cannot run a flat top piston in your bike unless you mod the head to suit.It will have low compression and not be optimised.

That is why it posted low compression even though it had a new top end when I got it.

Thanks a million.

 

[frankenbike]

The reverse is also true...I put a stock domed piston in my 1998 KX250 when the Tom Morgan Racing head mods called for a flat top piston. The result...it ran fine, but had lower compression than expected. Eric Gorr confirmed this per a telephone call.

Brian
1998 KX250
2003 KX250