[Schurkey]

Vacuum port on the runner for #3 cylinder? A big-enough vacuum leak can make the mixture too lean to burn.

[Tim Corcoran]

Originally Posted by Schurkey

Vacuum port on the runner for #3 cylinder? A big-enough vacuum leak can make the mixture too lean to burn.

Schurkey was spot on in post number 14. I suspected a vacuum leak from the very beginning but for the life of me couldn't figure out where it could be. I even pulled the carb off and made sure the gasket was covering all the right places. I believe I did all the correct trouble shooting steps but just couldn't figure it out until I pulled the intake manifold. When I was elongating the pushrod holes so I could use 1.65 rockers I got kind of carried away and broke through in a couple places. My machinist gave me some two part putty epoxy and he said it would be fine. Maybe I sanded it too thin but obviously it didn't hold. Now I need to fix these holes with something that will stay put.

[Gach]

Yep that picture explains it all. That baby is sucking in some oil ( Big vacuum leak )

[Gach]

If you can, put a sleeve down that hole, only because the Apoxy is a hit or miss. It’ll come out again when you lease expect it