petrol pump/diaphram???

pike247

Cadet
Joined
Sep 28, 2008
Messages
11
Hi all

I have a Mercury 80hp 4 cylinder serial No 9300005 I believe this makes it somewhere between 81-83ish. I am having trouble keeping the petrol bulb hard. I will start at the begining... when I was pumpping the primer bulb it was getting hard sometimes then sometimes not. After a bit of investigating I took off the petrol pump and discovered the two washers inside were perished. I managed to find replacments and changed them. This cured the problem with the primer bulb in as much as it seemed to pump up and stay hard. However when I went out on the boat I had to have someone in the back pumping the primer bulb to keep the petrol supply going. If I dont pump it the bulb goes soft and the engine stalls due to lack of petrol. What I need to know is do these petrol pumps just work on a vacuum or is it an actual pump? when I took it apart I couldnt really see a pump as such it just looked like it works on a vacuum if it does I presume I need a new diaphram kit as it would appear it is not air tight. Any info or suggestions would be appriciated.

Regards Pike.:confused:
 

TheWoodCrafter

Chief Petty Officer
Joined
Nov 20, 2007
Messages
414
Re: petrol pump/diaphram???

Petrol!!
You must be from the other side of the pond.
Welcome anyway.

I am pretty sure you have a vacuum actuated pump. It's operated from crankcase pressure.
Get a new pump kit and you'll be good to go.
 

pike247

Cadet
Joined
Sep 28, 2008
Messages
11
Re: petrol pump/diaphram???

Hi

Yes I am from England :) thankyou for your quick response I will get the new kit and hopefully it will do the trick.

Regards Pike.
 
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