thedonz

I need to check the fuel delivery system on the boat to confirm there is no blockage, how do I check these valves at the tank?

thedonz

anyone?

Strip Poker 388

iTrader: (6)

I remember something about a test? take the fuel line after the pump and let it flow into a 1 gall container . it should fill it up in lest than a minute.

thedonz

thanks for responding Strip,

is this done with the engine running? at idle? how will the carbs be supplied if I disconnect the line?

Strip Poker 388

iTrader: (6)

Just with the key on. The fuel line will be off the motor, it want run

Maybe Rum Runner will chime in with the exact test.

Rob

thedonz

Rum Runner, you around????

hillbilly24

The best way to check the fuel system is a fuel vacumn test, tee a vacumn guage in line just before the fuel pump and check the reading with the engine running throughout the RPM range, it should not exceed 2" of vacumn. A standard vacumn guauge works fine for this just make sure it has fine increments, also you may want to use one that you dont care about becuase fuel can damage the diaghram in them. Cole-Palmer makes a nice digitail guage that is not afected by fuel or oil but it costs about 200 bucks, maybe a little much for a one time thing.

Strip Poker 388

iTrader: (6)

Never heard of that one before ?Could your explain how that would work.

Would it depend on if the fuel pump can suck?

Rob

tomcat

Test checks the pressure loss from tank to pump. 2" Hg is about 1 psi. It's a neat idea. Does the 2 "Hg value include a good water fuel separator?

Test doesn't tell you if the pumps are supplying enough fuel for the engine. It assumes that the pump is/was doing the job and checks for restriction on the pump supply. Test could mislead you if the pump is worn out and simply can't develop much vacuum on the inlet side (or pressure on the outlet side).

What are those valves for anyway?

hillbilly24

Yes it does depend on a good fuel pump, first you need to check the output pressure of pump, if it is correrct then move to the vacumn test. He said he needed to check the fuel supply system so I assumed he was talking about the tank, anti siphon, and valves Etc, and had already checked the pump and engine side of the sysytem.