77 vapor canister piping

[beardface]

The 77 originally came with only 2 ports on top of the canister. I have the assembly manual and it shows one port to the gas tank and one to the carburetor, however it does not clearly indicate if it should go to ported vacuum or manifold vacuum. It also doe not show any type of restrictor or anything else inline, just a hose directly from carb to canister.
the carb is not original, so any help on correct vacuum source (ported or manifold) would be appreciated.
As this is only a 2 port device, any drawings showing ported vacuum and pcv vacuum to a switch valve on top of the canister is not applicable to the 77.
Thanks

 

[Tom Bryant]

Seems to me that you would wand a full time vacuum to keep the fuel tank vapors purged.

Tom