fuelpump problems?

rolmops

Vice Admiral
Joined
Feb 24, 2002
Messages
5,299
In trying to get my 1967 merc 500 to run,I discovered that when I pump fuel with the ball in the line, fuel will start leaking out of the top carburetor.This is a side bowl(back drag carburetor).Before tearing into the carburator I wonder if this could be because of a leaking diaphragm in the fuel pump.Most of my outboard experience is with pre 1960 engines and I feel out of my depth with this "modern" machine.<br />Thanks in advance for your help,Rolmops.
 

WillyBWright

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Joined
Dec 29, 2003
Messages
8,200
Re: fuelpump problems?

So, you're into stone axes and clubs, are you. Me too.<br /><br />That's not unusual. The float valves in those carbs are wimpy! It's real easy to overcome them with the primer bulb. In fact you kinda have to in order to get those relics to start. If you squeeze hard, it'll puke gas out of the carb vent. If you squeeze soft and it doesn't , you're probably okay.<br /><br />Good luck with that motor. When they're in good shape...well I don't think Merc made a better motor, myself. But those carbs are a MAJOR pain in the you know where to get to.
 

weimy

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Joined
Jul 2, 2004
Messages
19
Re: fuelpump problems?

I had a 1967 mercury 9.8 horse. Tried to get it started and 3 pulls later I had 3 ft flames coming from the engine. After I put the fire out I later discovered the carbs were leaking gas. Be careful and have a fire extingusher near by.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,030
Re: fuelpump problems?

Weimy, Were you using ether? Never had one catch fire, except as described below. <br /><br />One of my life's lessons: If you spray ether into a cranking engine it will catch fire!:mad<br /><br />Corollary: If you need to spray ether into a cranking engine, it ain't gonna start anyway! :rolleyes:
 

weimy

Cadet
Joined
Jul 2, 2004
Messages
19
Re: fuelpump problems?

No all I was using is 87 octane fuel mixed 50:1. My guess was maybe one of the dogs when I pulled the rope sparked and shot by the leaking carb. I don't know. But I sure got rid of it right away.
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: fuelpump problems?

sticking float maybe?<br />check for dirt in the needle/seat rolmops.<br />sometimes if you tap on bowl with but of screwdriver<br />it will un-stick float. fuel pump kits r cheap/easy<br />and first thing I would do (after compression test)<br />good luck,<br />M.Y.
 
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