changing fuel pump from VRO

[medic2051]

Motor is a Johnson 50 (J50PLSSM) year 2000. Orginally had VRO, which was disconnected. This summer we have had a several occasions where the motor "surges" and/or stalls, just as if the fuel tanks are almost empty. I was able to keep the motor from stalling by manually pumping the bulb on the fuel line. I replaced the inline fuel filter on the external tanks, switched the tanks.It still happened. My repair guy has taken the boat out twice, can't duplicate the symptoms.
Question...he mentioned replacing the fuel line coming off the portable tanks (about 4 years old) Is that a likely cause? He also mentioned replacing the fuel pump with a non-VRO type, which would cost $300 installed.
I'm considering purchasing a manual and replacing the pump myself: Is it more difficult to "retrofit" this motor to use a non-VRO fuel pump? I replaced my last fuel pump on my 1975 johnson 50, that was easy.

Thanks guys.

 

[tashasdaddy]

Re: changing fuel pump from VRO

never done the retro fit. but the surging/stall could be water or air from the almost empty tank.

 

[medic2051]

Re: changing fuel pump from VRO

Yeah, that's what it seemed like, but tank was full. what's the life expectancy on an external portable tank fuel line? If I squeeze the bulb and it stays hard, does that mean the line is good?

 

[ezeke]

Re: changing fuel pump from VRO

I would guess that your mechanic wants do is to put one of the premix pumps [part #5007422] in that looks like the VRO but does not have the oil side. Those pumps list for around $200.

The other alternative is to use a conventional fuel pump and eliminate the pulse limiter.

Also, if the pulse limiter is fouled, it can cause some of the symtoms of a failing pump. It can be cleaned with carburetor cleaner.

 

[medic2051]

Re: changing fuel pump from VRO

That's something I'm not familiar with. would a manual cover how to do that?

 

[medic2051]

Re: changing fuel pump from VRO

The pulse limiter part, I mean...not familiar with that

 

[ezeke]

Re: changing fuel pump from VRO

The pulse limiter isn't needed on the older conventional pumps.

The pulse limiter is basically a check valve that functions when the velocity reaches a certain point and stops the pulse from putting too much pressure on the VRO pump. You just need to take it off and clean it and blow hard enough on it to close the valve. If it is clean and won't close, it has to be replaced.