88 85hp Fuel Pump Question (with pics)

[cjac2879]

So i finally go to removing my fuel pump today to check the diaphragm and check valves. The diaphragm looks to be in good shape.. there are no visible holes, and the rubber feels good and not brittle.

The check valves, I pulled out the middle one, and can blow air throw both directions, I havnt pulled out the other 2 yet, but I cannot blow air through the outlet tube back into the check valve, and obviously the third one I cant check without removal.

With that said, upon removal of the pump, I found an black oily substance behind the pump where is goes towards the cylinder (see pictures), The 2 gaskets were in pretty rough shape when I removed them.. Is this normal, and if not, could it be the cause of the engine stalling when accelerating?

Last question.. I read somewhere on here that the new check valves are black/charcoal in color, and that bad ones are clear/translucent orange, by looking at the pics, do these look to be affected by ethanol??

Thanks everybody in advance

First 2 pics show the oily substance (gas??)

Bad gasket causing a leak into cylinder?

Check Valves

 

[pnwboat]

Re: 88 85hp Fuel Pump Question (with pics)

So i finally go to removing my fuel pump today to check the diaphragm and check valves. The diaphragm looks to be in good shape.. there are no visible holes, and the rubber feels good and not brittle.
If I don't know how old the diaphragm is, I usually change it to be on the safe side. It's just personal preference.

The check valves, I pulled out the middle one, and can blow air throw both directions, I havnt pulled out the other 2 yet, but I cannot blow air through the outlet tube back into the check valve, and obviously the third one I cant check without removal.
These are "one way" check valves. If you can blow through it in both directions, it's bad.

With that said, upon removal of the pump, I found an black oily substance behind the pump where is goes towards the cylinder (see pictures), The 2 gaskets were in pretty rough shape when I removed them.. Is this normal, and if not, could it be the cause of the engine stalling when accelerating?
That's just fuel/oil residue. The cover that you removed is part of the passage that feeds the fuel mixture into the cylinders. Looks like the gasket may have been leaking a bit. Hard to say if it was affecting performance. Most likely the bad check valve was causing problems. Regardless the gasket(s) should be replaced.

Last question.. I read somewhere on here that the new check valves are black/charcoal in color, and that bad ones are clear/translucent orange, by looking at the pics, do these look to be affected by ethanol??
I always replace the orange colored check valves. I suspect that the newer gas may cause them to swell a bit which makes them stick and not function properly.

 

[cjac2879]

Re: 88 85hp Fuel Pump Question (with pics)

I got my new pump in the mail today, and I noticed there is an additional fitting leading into the engine area (see pics below)... Everything else is the exact same, and this is the model number for my boat... What is this fitting for, and is it needed, can I just use the same "metal piece" (not sure the name) from the old pump

 

[Frank Acampora]

Re: 88 85hp Fuel Pump Question (with pics)

That is the oil recirculation fitting. Oil from the bottom of the recirculating plate is delivered to the cylinder (varies from engine to engine, usually the top on 3 cylinders) to be burned. If you do not need it on that bypass cover, simply use a rubber plug on it or remove it and plug the hole with a 1/8 NPT pipe plug

UH! Hope you got a COMPLETE pump, "cause that base is newer and will not accept your cover as shown in the photos.--Yeah, bolt pattern is the same but the cover itself is different.

 

[cjac2879]

Re: 88 85hp Fuel Pump Question (with pics)

Yes, I did get a complete pump unit, so im not worried...

Can I not use my old base "the one in the pics" with the new body unit?

 

[Frank Acampora]

Re: 88 85hp Fuel Pump Question (with pics)

Might be possible--I never tried it. But the hole is there, just raised to match the new pump. Worst that could happen is it punches a hole in the diaphragm and that's easy to replace--even on the water. However, you will get less movement and therefore less volume from the diaphragm. Hey! Try it and see, then let everyone on the forum know the results--always learning

 

[cjac2879]

Re: 88 85hp Fuel Pump Question (with pics)

Thanks alot frank... Im gonna compare them tomorrow, I may just get a plug for the new base... I need to order the gasket anyways, so I am going to have to wait for them