Hello,

The twin Zenith carbs are complex but amazingly reliable and well mannered when put right. Most owners give up on them because they do not understand them. These early versions (pre Emmision) are the best. I have a copy of the factory set up procedure I can email you if you like. All re-build parts are available. Try aftermarket suppliers and save lots. You'll need a few gaskets, the acceleration discharge pumps (early were leather later were neoprene). Replace with the neoprene will solve the leather dry-out issue from long storage. You will need the secondary rubber diaphrams, and possibly some mounting gaskets (at manifold). Run a tiny wire down the accelerator discharge tube to clear it. This tube simply is pressed into its bore and can be removed from its tappered hole with needle nose pliers. The rest is understanding the correct way to sync the carbs and set up the idle. The complex automatic chokes and cold idle adjustment will take some studying before you will realize how it works.

I am good with these carbs so just ask questions.