Zenith fuel percolation fix - need feedback please

[1QuickS]

Most of us know that PMO has a tool to drill holes in the top cover of Weber carbs to direct percolating fuel down the throttle bores and not out the vent pipes to spill onto the exhaust system. The Zeniths suffer the same percolation issue but their top cover design is "inverted" from the Weber design so fuel will pass up through the vent pipe, into the air cleaner housing and then dribble down onto the exhaust and/or collect in the reservoirs of the top cover itself.

I have an approach for redirecting percolating fuel into the throttle bores like the Weber fix, only different and I would like feedback on it. The Zenith top covers have a cast-in fuel gallery that is undrilled. If it is drilled so that it opens into the throttle bore then fuel would be spilled there before it comes up the vent pipe; see hole #1. If fuel does make it up the pipe and dribbles down the holes in the air cleaner for the emulsion tubes then a second hole through the wall for the throttle bore would drain this fuel which would otherwise accumulate; see hole #2. I have identified the holes in the pictures attached for clarity.







Paul Abbott
Performance Oriented