[CB550 Matt]

Picked this up at the mt Vernon swap meet yesterday. It has the smaller bolt sizes for the headbolts and the early casting marks. I has a good amount of meat on it for a resurface, but it does not have the hose between the carbs. Here is a side by side comparison. Any ideas?

 

[Destralo Roach]

I'd say early 63-65 you can have to holes machined out to the largeer size and it will work on the latter barels...

 

[CB550 Matt]

I was thinking the same thing on the age. I am not sure the benifits of putting the piping in, maybe for easier syncing of the carbs. There was a obscure reference to generating more power without the older heads. I am unsure if there is any truth to that.

if so maybe it was the motorcycle gods smiling down on me as I still plan to build it up to take down to speedweek in 5 years. Of course that was my plan 5 years ago as well.

Anyone need a free wrench or gopher down there this year?

 

[M.O.Ther]

The balance tube was a new feature for model year 1966. It does help with street tunability, not sure about WFO horsepower. The '66 also got a new larger intake valve, definitely a plus in the HP dept.