fuel pump.

lilyduck

Cadet
Joined
May 11, 2005
Messages
11
I got a 69' 25 hp rude that is having trouble with pumping gas into the engine. Here is what I have done so far. I have replaced the tank and the gas lines all the way to the fuel filter/pump and all the way to the bottom of th carb. Everything is new.<br /><br />I have replcaed the gasket and the filter in the fuel filter as I thought there may be a small leak, which there was. But the leak is no longer there. I started to tear down the actual fuel pump assembly thinking that this was the problem. It has three peices to it the front peice is where the gas enters from the fuel filter. Second peice and third peice both have a thin rubber peice. There is a spring in the inside that was laying down. Doesnt look as it was it correct so I stood the spring back up and put back the pump. I was trying to fix this becase I have already put in 15 bucks into the fuel pump/filter where the whole unit new cost 55.00 if you think that this is the case. I guess I can just purchase that, just want to make sure that I have covereed everything before buying another part!<br /><br />Thanks Guys!
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: fuel pump.

That little fuel pump can be a real puzzle to put back together. In this case, I would replace it.
 

jfm1

Petty Officer 1st Class
Joined
May 14, 2004
Messages
355
Re: fuel pump.

are you sure its the fuel pump ? if the motor been sitting along time I would get a carb kit a clean the carb and rebuild it
 

lilyduck

Cadet
Joined
May 11, 2005
Messages
11
Re: fuel pump.

I am pretty sure that its the fuel pump as the motor ran al last year and ran the first time out this year, always worked in the past, but had to squeeze the ball the whole way back to the launch to keep it from stalling. So that was why I guessed that it was the fuel pump.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: fuel pump.

Speaking generically the pump is laid out logically.The diaphram is actuated by crankcase pulsations.As the diaphram moves back and forth gas is drawn in through the inlet valve, when the diaphram moves the other way it pushes the gas out through the outlet valve.These one way valves usually have springs that hold them closed if they are stiff or gummed up or damaged it won't work.If the diaphram has a hole it won't work correctly.<br /> On some motors the pulse port can become plugged<br />so it can't pulse the pump.If there is a hose on the pulse port it could be plugged.<br /> Does the primer bulb pump gas?If all is well the primer bulb should be able to supply gas to run the motor.If it does then it would appear the pump is bad.
 

lilyduck

Cadet
Joined
May 11, 2005
Messages
11
Re: fuel pump.

The primer bulb is supplying the gas to the motor, thats shy I thought that it was the fuel pump. You are dead on, I was thinking that one of the diaphrams was rippped or had a hole in it. I guess I will just go with a new pump and see what happens. The guys at the marina said that if id dont fix the problem I can bring it back. So a little more motivation.
 
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