85 650 vs 700

[Gene]

Ok, I know the displacement is different, the 650 bore vs stroke is 60x58, the 700 67x49. The 700 has a mini fairing and a different tank. According to what I've read, the 700 has a completely different engine design, but I'm not sure what that means. I could be wrong, but I wonder if you could rebuild a 650 into a 700 by replacing the crankshaft and top end. Can anyone fill me in?

[ExTex]

They are totally different engines. 
The 700 is based on the 750 engine and shares little/no parts with the 550 & 650 engines.

[Gene]

 From what I've read, the 550 is only a SOHC, while the 83 to 85 650/700/750 are all DOHC

[ExTex]

The 1982 650 was a SOHC but the 1983 550 & 650 are DOHC engines.

Have a good day

[romzrx]

Ok, I know the displacement is different, the 650 bore vs stroke is 60x58, the 700 67x49. The 700 has a mini fairing and a different tank. According to what I've read, the 700 has a completely different engine design, but I'm not sure what that means. I could be wrong, but I wonder if you could rebuild a 650 into a 700 by replacing the crankshaft and top end. Can anyone fill me in?

I just bought a 650 Nighthawk and the PO replace the cylinder/ pistons with 700 Nighthawk.
I will check and report back.