Vac questions

[skynyrdcat]

Just curious...

How much vac should it take to pull fuel up to the pump on a typical outboard?

at what points would you look for leak or restriction?

How much vac should be present on the back (tank side) of the fuel pump?

No specific issues in mind, was just mulling over some test procedures.

 

[seahorse5]

Re: Vac questions

Johnson-Evinrude states that there should never be more than 4" Hg vaccuum in a fuel system. Yamaha says a max of 6" Hg.

A good fuel system with a quality anti-siphon valve and a spin on fuel filter will test out about 3.0-3.5" Hg at just over 20 gallons per hour.