• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

Head Cast Numbers vs K - F1 - F2

Jeff K2

CB750 Member
Messages
19
Reaction score
0
Points
1
Location
Aguanga, California
I may be the last person in the world to know this, but in case anyone else does not, I have decoded the head numbers for SOHC 750s.

K - cannot find any number on the head, although the head was modified by RC eng.
F1 - 300_X - on the rear/upper/center fin
F2 - 410_X - on the rear/upper/center fin

I believe I have also figured out some of the head to cyl. compatibility;

You can put a K or F2 head on a F1 cyl., but you should pay close attention to the return oil flow galleys. Either seal them all or know where the oil will go.

NEVER put a F1 head on a K or F2 cyl., without providing O-ring seals at the outer oil return galleys AND adding oil return flow paths in the head for ALL of the outer valves.

F2 might work on a K cyl. as the valve galleys are joined. I may wrong as I do not have a F2 cyl to verify the return oil galleys.

Jeff K2
 
Back
Top