[SpeedracerFTP]

I want to gt an old school yamaha rd400 which is 2 stroke 2 cylinder. these bikes are capable of some decent HP. I want to know what would be a good thickness to deck of the heads to get a decent performance gain? Id also be doing a port and polish. I dunno if 1 or 2 mm, or.010" or .02 would be correct? any ideas?

 

[ZXLNT]

Maybe check with these guys..

http://www.trinityracing.com/

 

[93FZR1K]

Another place to get info on RD's

Linky