What F type do I have?

[ThomNL]

Hello all,

I just bought a CB750 this weekend. It was sold to me as an F1 by a reliable person that races a lot with CB750's so he knows a few things about them. But, here's the deal. It is registered as an F2. The VIN is CB750F-1017... which from the information online should be an F0. The engine number is CB750E-2531... which would be an F1. So, can anyone tell me what I have?

 

[dirtdigger]

1975 F0 Frame. If the engine isnt a cb750FE-*** then Its either an early production 75 or someone swapped in a standard K motor I am thinking.