fuel pump diaphragm: holes and gas mix pumping in crankcase.

[777funk]

Is there anything that could cause damage to the diaphragm or is this likely just routine wear and tear?

I have a new one but I want to evaluate any probable causes if something could be wrong before I replace it.

I wanted to use the boat this week and cut an innertube to fit as a temp fix. It went through that in one run.

 

[GA_Boater]

Stop thinking and replace the diaphragm with a new piece. They stretch and wear out. Really, an innertube?

 

[777funk]

In a pinch on a private 40 acre (small) lake with my dad wanting to fish and no oem replacement part... Yes! An innertube. It got us through the trip. Why not.

I ordered the OEM part same day BTW. So yes, innertube or nothing. The innertube diaphragm was worth what I paid for it and we had a blast on the water fishing vs sitting in my parents hotel room.

 

[WinnerCougar74]

Good job on the inner tube idea. We have to think on our feet with these old motors. Just keep them in stock from now on right. They are about $20. Everyone says they are a maintenance item.

 

[777funk]

Absolutely! Was just making sure i didn't have another problem (i.e. Bad check valve etc) since the innertube make shift part looked just like the old diaphragm in how it punctured.

 

[WinnerCougar74]

I think an electric fuel pump might be an interesting idea but some say it's not safe.

 

[puffitu]

Man if I had a dime for ever time I had to rig something together to either get back to the dock or just make er work for the day!? Nothing wrong with using your brain, ingenuity and what ever is laying around to save the day. I was having a overcharging issue and used a regulator from a snow mobile. Made a transom bracket out of a bike stand, there are more but afraid to mention. As long as you’re not risking blowing yourself up or anyone else; you do what you gotta do especially when parts for these motors are sometimes unavailable

 

[jerryjerry05]

I like the idea of the inner tube!!

Had a float bowl fall off an OLD 40hp
Johnson carb.16ft. Starcraft.
The gasket went somewhere??
I fixed the motor with a piece of electrical tape as
a seal on the bowl.
We were out on Saginaw Bay in Michigan and were
fighting 12ft. seas when the bowl fell off.

Look around, you can find the diaphragms for as low as $6

It takes one little cough, backfire to blow the diaphragm.

Bought a boat with twin 88/85 Forces.
The guy used it for running 60-80mi. trips out of St.Pete's
I was doing regular maint. and was checking the pumps.
Both pumps had 2 diaphragms???
I imagine they wouldn't go bad.

 

[puffitu]

Lol
so 2 pumps a good idea???

 

[emoney]

Usually it's just the gas that eats away those diaphragms, so odds are nothing else is wrong. I've pulled them off so paper thin I couldn't imagine how the motor kept running.

 

[jerryjerry05]

Gas eating through the diaphragm??
What kind of gas you burning??

Depending on the manufacturer the thickness can
be varied as the manufacturer??
Most time they go bad because of age, and lack of use.
They set for months/years and then someone pumps
the ball and the diaphragm rips.
A backfire or even a stutter can poke a hole in one too.

Not 2 pumps, 2 diaphragms on each pump.
They were working fine, just wanted to be sure before I went
20 mi.out in the Atlantic???

Electric fuel pump: if it's installed right then it's ok.
But easier to make sure the one you have is right.

 

[The Force power]

opcorn:

 

[puffitu]

Thanks guys!!
ill post back after I put a new cable on, new pump diaphragm and re Linc everything again

 

[roscoe]

The 3 most common causes of diaphram failure in no particular order. IMO.

Early diaphragms were not ethanol resistant, and then they started adding ethanol to our fuel, they are now.

Engine backfire causing too much pressure on diaphram.

And simply age, things don't stay soft and pliable forever.