Fuel pump test..?

[frustratedboater]

All,
I've got a 78' Johnson 6hp and I need to test the fuel pump on it. Is there a fail-proof way to test the pump? I'm just not sure exactly how to tell whether it operates or not other than pulling off the hose and creating a mess! Your help is appreciated,

~FB~

 

[F_R]

Re: Fuel pump test..?

There are two ways to test it. #1 is does it supply enough fuel to keep the motor running? #2 is with a fuel pump tester gauge. You tee it into the outlet hose and read the pressure while it is running at all speeds. It's nothing but a pressure gauge that reads low pressures in the under 10 psi range.

 

[frustratedboater]

Re: Fuel pump test..?

F-R,
Hey thanks for the info. Always wondered how to test them. The engine runs for abit then quits, which I suspect that it is dirt or junk in the fuel circuit somewhere. The fact that it runs tells me it's most likely fine, but would like to rule it out! I appreciate it,

~FB~

PS- Is there a source as to where I could look into buying a gauge? To save a few $$, I'm sure I could make one...?

 

[Mas]

Re: Fuel pump test..?

When it is about to die, try pumping the primer bulb and see if your rpms increase. If so, your fuel pump is pprobably bad.

MAS

 

[F_R]

Re: Fuel pump test..?

mas is right, see if you can keep it running by pumping the bulb. You are doing the fuel pump's job when you do that.

Fuel pump test gauges are usually sold as combination vacuum/fuel pressure gauges, reading both sides of zero. Try a discount auto store, or Harbor Freight. You probaby can find a geat range of prices from very expensive for a Snap-On to very cheap for a Harbor Freight.

 

[frustratedboater]

Re: Fuel pump test..?

You know, I would of thought that common sense would apply here, but until someone else clears the fog from my brain... Of course the primer bulb method would indicate a faulty pump...! Thanks!

I'm not sure yet before I dive into it, but just in case, at least I know what to look for. I do ""appreciate"" the tool tip and diagnose technique,

~FB~