Topic: whats the difference in heads?

[Doggie]

Does anyone know what the difference is between a 1980 CB650 head and a 1981 CB650 head?
 Can they be swapped out?
                                           Thanks, Doug

[MiGhost]

In 81 the intake port spacing in the cylinder head was changed to a match the CV carbs. The 80 cylinder head will bolt in place of the 81 head, but the 80 head will need the mechanical carbs to match the intake spacing.

[Doggie]

Great...Thats what I needed to know.      Thanks, Doug

[754]

I have a brand new 650 head if anyone needs one. Have to check the spacing.

[MiGhost]

I have a brand new 650 head if anyone needs one. Have to check the spacing.

Frank, You can tell the difference between the early, and late 650 heads by the bottom 2 fins on the intake side. The early 79-80 mechanical carb head has the fins straight across the entire length. The late 81-82 CV carb head has the fins cut back under the intake ports.

[Doggie]

Thanks again for the help.   You guys are sharp!!     Doug