Yamaha 64x 760 head

[big al]

I’m looking to mill my 760 head and I don’t know how much to tell my machinist to take off. I still want to run pump gas 93 octane of course. Any input will be appreciated!

 

[bored&stroked]

I run 220psi on 93ish octane.
Pump gas safe is different for everyone's setup and riding style. A closed course racer would blow my engine up in like 45 seconds lol.
If you mill enough off for that much compression, its gonna need new domes cut into it as well.

 

[big al]

I run 220psi on 93ish octane.
Pump gas safe is different for everyone's setup and riding style. A closed course racer would blow my engine up in like 45 seconds lol.
If you mill enough off for that much compression, its gonna need new domes cut into it as well.

I’m just looking for something to give it a little bit more punch nothing to extreme. Maybe around 180 psi.