Manometer! (doo doo do-do-do)
 

This is what I made to sync my carbs. Not sure how long the cheap tubing will last but it's only $3 for 10' of it. I used 2-cycle oil for the fluid. It was a greenish blue color and easy to see. TV cable tacks worked great to hold the hose to a 2x4. When I cleaned the carbs I ran 2 hoses to an easy access point. I'll zip-tie them out of the way later. It worked great and the difference after syncing is quite noticeable. Thought I'd share.

https://www.superhawkforum.com/forum...1&d=1338758372

https://www.superhawkforum.com/forum...1&d=1338758391