Mechanical Fuel Pump

[weephee]

I don't know if anyone has ever experienced this, but last year I purchased a kit from Moyer Marine and rebuilt my mechanical fuel pump. Worked great all season. Took the boat out for the winter and this spring before launch, I tried to start the engine. No go. Left the boat and when I returned, there was a lot of gas in the engine bilge. The mechanical fuel pump was leaking a lot. Took it out and took it apart and the rubber diaphram was decomposing on the under side to a black mush. The top side where it interacts with the gas was fine. The diaphram was totally destroyed. I talked to Don Moyer about it and he has never heard of it happening. He was gracious enough to send me another kit but I really need to know what is happening. It almost looks like it might have melted but the engine did not over heat. Usually runs at 140 degrees. I have returned the diaphram to Moyer for investigation. Any ideas. Thanks
Larry

[sastanley]

Larry, maybe a bad batch? I am sure Don will report his findings to you once he examines the damaged diaphragm.

I have not had any trouble with my 2009 Moyer kit mech pump rebuild.

[ndutton]

I've not had any trouble with my electric fuel pump either

[roadnsky]

Originally Posted by ndutton

I've not had any trouble with my electric fuel pump either

I'm with Neil here...

[systemek]

I too, am a convert to an electrical pump and I am not going back. If anyone here is interested in my old crusty mechanical pump, it is all yours.........

[13jeff13]

Originally Posted by systemek

I too, am a convert to an electrical pump and I am not going back. If anyone here is interested in my old crusty mechanical pump, it is all yours.........

Wow! Makes me happy I opted for the MMI electric fuel pump conversion kit. I really like the idea of a keep it simple mechanical pump. But the electric fuel pump conversion kit made more financial sense for me.

[systemek]

Just following the big boys here.....probably a good idea to keep a mechanical pump on board for repairs but I think I will stick with an electrical backup....less moving parts

[67c&ccorv]

I'll stick with the mechanical thanks.



Wondering if this has anything to do with additives in the fuel attacking the rubber compound in the seal. One of the reasons why draining the fuel pump for winter storage is a must.

[smosher]

I also switched over to the electronic fuel pump. I did it so to avoid the issue
of gas bypassing the membrane and going into the crankcase. I didn't have any
issues with the mechanical pump. The changeover was a preventive measure

My Pressure with the mechanical pump was 4 psi and with the facet is 5 psi.
The facet is mounted on the brkt on the engine, with a racor water/gas separator filter.

Steve

[weephee]

The only additive I used was to put a small amount of Marvel Oil in the fuel tank at the end of the season. I wouldn't expect that to cause a problem. I use automotive gas from gas station vs marine gas. Would that make a difference

[hanleyclifford]

IIRC when ethanol made its entry into our lives some had trouble with fuel lines dissolving and leaking. Newer lines are rated for ethanol. Maybe the part in question was made from old stock.

[roadnsky]

Originally Posted by weephee

I use automotive gas from gas station vs marine gas. Would that make a difference

Do you know if the gas was Ethanol free or not?

[weephee]

Sorry, don't know about the ethanol but doesn't all automotive gas have ethanol to some degree. I will report back when I hear from Moyer Marine. Thanks all for your replies.
Larry