Re: 6v fuel pump wiring question

Posted by Joe Santana On 2011/10/23 12:14:07

Thanks, Howard.

I think one of these articles mentioned a switch that did both.

I found it. It's a 3-way testing toggle switch. Off, Spring-tensioned On for priming, and an On for continuous use. In the same paragraph the article also warms not to connect to Starter switch because it's possible to prime the carburetor without having the ignition on and no current to the distributor.

So a 3-way toggle is what I'll look for today. That and a shield of some kind to keep the pump, valve and gauge clean.

EDIT:
Thanks, Saltydog,

I'll add a switch. There were two main reasons in the article for not adding the pump directly in the fuel line. One is the pressure is higher than the specs for older carbs, like 7-10 PSI, but claasics' carburetors need typically 3-5 PSI. 7 pounds overwhelms the float needle and can run the engine too rich. This is corrected by using a fuel pressure regulator in the line, or the setup I have...valve and gauge.

The second reason is, if the diagram in the mechanical fuel goes bad, the electric pump will keep on pumping (if you leave it on), pumping gas into the crank case. It isn't easy to notice until one day you check the oil and it smells like gas and it's over the full line.

Joe, instant expert (I went back and re-read)