'99 50 hp 4 stroke Merc dumping fuel from the fuel pump

[jigngrub]

Was checking my engine out today after the resto so I could go out tomorrow and found a fuel leak.

Every time I squeeze the primer bulb fuel squirts out of this black box on the back of the engine.

It's where the main fuel line connects and 2 other fuel lines feed the 4 carbs, I'm guessing it's the fuel pump? I tightened up the 4 screws on the metal cover but that didn't help, so I figure I need to replace it?

Do I need any special tools for this job, any special procedures? Since I've never done this before should I just take it to my mechanic?

Any and all help greatly appreciated.

 

[Faztbullet]

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Where are the correct fuel ties??? Have you had the pump off? Over-tightening can cause the chamber body to crack which is not sold,you have to buy the complete pump if cracked.

 

[jigngrub]

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Where are the correct fuel ties??? Have you had the pump off? Over-tightening can cause the chamber body to crack which is not sold,you have to buy the complete pump if cracked.

If I knew where the correct fuel ties were I probably wouldn't have even posted this question. I suspect the correct fuel ties were taken off and not properly replaced by an idiot that called himself a professional mechanic (and worked for a national chain marine repair shop) and ripped me off for a $600 on a carb rebuild job a few years back... and I guess my good mechanic didn't notice they were gone when he vacuum synchronized my carbs like the idiot should have done.

I have never touched the pump before today. I don't think I overtightened anything, but I may have.

How much does a new pump cost?

 

[jigngrub]

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Well it looks like I'm going to try a partial rebuild because my marine dealer doesn't have one of these pumps in stock mainly, and secondly the thing is $167. I think I can get by with $41 in parts.

I'm going to replace the cover which has the gasket I suspect is leaking, the rear diaphragm, and the 2 check valves. If it works that's great, if not I'll buy a new pump and bite the bullet.

I'll also be installing the correct fuel ties.:facepalm:

 

[jigngrub]

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Uhh... thanks for the help everyone.


Not too much help here for fuel pumps eh?... but that's ok, I fingered it out myself.

My parts still haven't come in yet, but I decided to take the pump off and have a look see and do kind of a dry run.

As soon as I took the cover off I saw what my problem was.

The diaphragm directly underneath the cover had shrunk/slipped and wasn't being held in place by the cover gasket causing a gaping hole and fuel to leak out and air to be sucked in. I have this part on order, and it's $11.

 

[dunc333]

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

Re: '99 50 hp 4 stroke Merc dumping fuel under the cowl.

good post dude your lucky over there, in aus they stopped selling pump parts (kits) and you have to buy the whole pump assembly now ,just another merc rippoff""""""""""""