Golden Jubilee
Posts: 5211
Joined: Thu Nov 29, 2012 9:28 pm
Location: Lyman, IA
Re: finding true top dead center
One thought, check and make sure there is vacuum to it, take the (power valve) cover and valve off the carb and run the engine, you should have vacuum coming up thru a little hole to the top of the carb. It comes from a drilling from the carb base, if you don't have vacuum than the power valve will be "on" all the time, and when you set the jet for cruise, it can't richen when higher power selected. The wrong base gasket or if the adaptor for the turbo doesn't have the drilling for the passage, no vacuum would get to the valve.
IIRC it doesn't tie into the main opening, thinking back to my engines with the Holley, there was a small hole next to the main opening on the manifold that went into the main plenum to supply the vacuum signal, and the base gasket had a small (1/8") hole off to one side, if you put the gasket on backwards it would plug off the hole.
I'm reaching back about 30 years for my info, so I could be wrong, but I think I remember having a problem with vacuum on a Dodge 225 and it was the base gasket.