1970 Johnson 9.5horse raise compression?

[andrew04]

I plan on replacing head gasket this winter, while block is apart i could just as easily have the block and/or head milled down a little in an attempt to up the compression. 1. Is this a good idea to get a little more power, and 2. is there enough room to remove a little material? Thanks! -Andrew

 

[shawnfish]

I plan on replacing head gasket this winter, while block is apart i could just as easily have the block and/or head milled down a little in an attempt to up the compression. 1. Is this a good idea to get a little more power, and 2. is there enough room to remove a little material? Thanks! -Andrew

whats your compression now?

 

[andrew04]

65-ish in both.

 

[shawnfish]

not sure but id check to see what good compression is for it before you go milling anything, also new pistons would probally do more for it than milling imo...

 

[zackie77]

my 1966 reads about that, been told thats normal for cranking on those, read" leroys ramblings" has good info on 9.5"s

 

[andrew04]

Yes, compression is normal for this motor. It is a fully functional 9.5, I'm wondering if I could bump up the compression and hp along with it.
Shawn, given that compression is okay, there is no need for new pistons, correct?