fuel pump might be going

[bob johnson]

motor is dying out often...not all the time..but often enough now...took a while before I got to squeezing the bulb just before it dies and finding that the the bulb was soft and that pumping it gave life back to the motor...because i go out alone most of the time!!

the book has a few tests..the first for leaks, then the second to check the pump

that on my agenda..

the question is can the long run I have from my tanks to the motor, have caused early pump failure???

20.5 lowe ultra roughneck
1995 johnson 115 ocean runner

the system is like this:

two portable 9 gallon tanks in storage compartments up under the front deck.
each tank has its own hose that feeds a three way valve under the console in the center of the boat...from there one line runs to the back to a fuel seperator and then I have an large inline clear fuel filter...and then the hose runs under the floor to the motor with another primer bulb on the rise to the motor.

I normall just use this last primer bulb to start the motor..

when i switch the vlave to use the other tank up front, i will usually pump the new tanks bulb.

I am not 100 % sure how good the terminal fittings are on the tank and quick disconnect at the tanks. but i checked the three way and it is solid, the connections at the seperator are solid and tight...

are the symtoms of an air leak the exact same as a weak or bad fuel pump?

the motor still has the factory fuel pump on it. but the oil is plugged off.

thanks

 

[oldcatamount]

Re: fuel pump might be going

Bob, The distance that fuel has to travel isn't as important as the height it has to rise to reach the motor. Rule of thumb is app.25". I doubt the distance would cause a pump to fail pre-maturely. I would suspect an air leak as you have a number of connections in your system.

 

[bob johnson]

Re: fuel pump might be going

bump....

what do i have B.O.????

anyone ??

bob

 

[ezeke]

Re: fuel pump might be going

The service manuals instruct that a vacuum gauge and short section of clear vinyl hose should be installed at the "fuel inlet fitting at the lower engine cover", and that the gauge "must not exceed" a reading of "4 in. of mercury (Hg) at any time." You should not see air bubbles in the clear hose.

It further states that if the reading exceeds 4 in. Hg, each fuel system component should be tested/

 

[bob johnson]

Re: fuel pump might be going

I am wondering if it might be cheaper and faster just to buy a standard fuel pump and pulse hose fitting... than the buy a vacum guage and a fuel pressure guage. then test and find I have to buythat stuff anyway.

Ill try the clear hose and look for bubbles anyway....

i think i read somewhere that hitting the primer would give info one way of the other based on if it clears the issue or doesnt change anything as a check of the fuel pump

right now it isnt a big issue, but I dont want to get stranded when a fuel pump goes bad and I could have taken care of it before hand.


bob

 

[ezeke]

Re: fuel pump might be going

What primer are you speaking of "hitting"?

If you are overloading your fuel pump and squeeze the primer bulb, then you may help the pump temporarily without discovering the cause of the obstruction.

On the other hand, if you overwork the pump and cause it to fail, replacing it without discovering the cause of the failure will only result in another pump failure.

A single lift pump is not capable of producing the same lift as the OMS on the 1995 115HP motor, or from any of the VRO or OMS pumps for that matter. You could probably do it with two lift pumps, but you need a second pulse for the second pump. I have a way of doing that if you are interested.

 

[bob johnson]

Re: fuel pump might be going

What primer are you speaking of "hitting"?

If you are overloading your fuel pump and squeeze the primer bulb, then you may help the pump temporarily without discovering the cause of the obstruction.

On the other hand, if you overwork the pump and cause it to fail, replacing it without discovering the cause of the failure will only result in another pump failure.

A single lift pump is not capable of producing the same lift as the OMS on the 1995 115HP motor, or from any of the VRO or OMS pumps for that matter. You could probably do it with two lift pumps, but you need a second pulse for the second pump. I have a way of doing that if you are interested.

the key primer....push in...I think it inject gas into the intake...bypassing the carbs...

it is LIKE a choke, but isnt a choke...previous motors I had the push in feature of the key was THE CHOKE....I think

I am just trying to be practicle.....thinking of just pre-empting the diagnosis..

and I do know it isnt the best way...but it is crunch time now...i have canvas work to do, I am altering a sailboat into a duck hunting boat and hunting season is almost here..

pus i have new pistons and bearings coming for my back up motor soon and I need to get it rebuilt...

lots on the plate...most i do is to make sure i dont have unexpected down time with the boat....

if I go with the standard style fuel pump(S) on this motor, will i still use the fuel bracket assembly????? seems to have its own float nd valve....I think it is also a vapor seperator...

learning as i go...

I become and expert in all my problems by default!!

thanks for helping me

id love to hear about the set up that could aloow me to run two pumps

bob

 

[bkwapisz]

Re: fuel pump might be going

If the tanks have quick disonnects (and I'd assume they do since you said they're removable) then on a cost basis it would probably be best to start by replacing those first as they're cheap. Then check all the fittings in the fuel line from there and make sure there's no leaks. If that doesn't do it, then I would go to the pump. I replaced mine with the appropriate pump and it ended up solving all my issues.

If the VRO (or whatever the designation is for that motor) has the oil disconnected then I would also make sure that the "plug" is air tight. If that's leaking air then you'd also get the airlock you speak of.

Just my $0.02.