I am sorry guys, I don't know what I was looking at. Carry on.

Alan, the wiring under the cowl is still in decent shape except the main battery leads which were cut off. There is sun damage but everything is still supple. The controll unit on the other hand is a terrible mess. The wiring just crumbles if you look at it wrong. The factory disconnect plugs are very pricy and thus will not be used again. I will just run all new leads and possibly pass the choke, start stop functions from the controll unit to individual switches on the dash.

The pic below is how I first did it, as it was when I took it apart. That pic does not match the image in the parts catalog. I have since rearranged the hoses to match the catalog. I'm just trying to make sure the catalog is correct, stranger things have happened. Originally there were identical quick release compression fittings on both lines which easily could have been switched.

I'm with Trey. The schematic shows the fuel line from the tank going to the flat upper part of the pump.....

I don't know... it looks like it comes out of the side of the fuel pump and goes to the carbs in the drawing. It looks like it comes out of the top of the fuel pump and goes to the carbs in the picture.

MercuryMarc wrote: Larry if your asking if you put the pump back together per the manual, it looks to be correct to me.

Larry if your asking if you put the pump back together per the manual, it looks to be correct to me.

Ive got a Mercury 500 that's about five years newer 77-78 with a stainless prop. Right now its pushing a 20' pontoon (Oh the humility) It will push it about 26mph and I've actually had someone in a fishing boat come up to me to see what was powering that relatively fast pontoon. Its been a good motor for me, very quiet at idle and smooth under power. I also like the fact that it has a pull strap under the cover for emergencies. Sometime in the seventies these motors supplier for the wiring was not great and the wiring coating will just fall off the wires after 15 years or so. I had to do a complete new wiring harness but other than that I've had no issues. I love my Merc. Maybe one day I'll find a short mid section for it and It'll find its way on the back of a Feather Craft and if the stars align I might be able to give Ray a run for his money in his Vagabond.

Ok, its not perfect but it is air and fluid tight even if you can still see the crack line. Ill will continue to look for NOS replacements but nothing showed up easily and spending $40 each min on used carbs to find cracked tubes was a gamble I did not what to take. Did I have to do it more than once, yes, several. Did I have to drill it out as it filled with solder, yes, more than once. Was it a pain, yes. Did it work, yes, I think so. I had to try. On close inspection the tube and top are two separate pieces bonded together somehow. If I had a mini lathe id have drilled out the tube and replaced with some small stock from the hobby shop. This should work for now, and is cost effective.

I have it back together, somewhat. I put it together the way I took it apart but I think the PO had the fuel lines backwards from the pump? I used new brass fittings, new fuel hose and new stainless clamps instead of the factory line which is over $60. I've got $23 in supplies (first money spent).

The parts catalog has it looking like this. Is this how the gas in and gas out are supposed to be? Id believe this over the way it was. I have since switched them but want to make sure.

Many of the early carb parts are available, Joe Poole, Oldmercs,com, Johns Old Mercury Site are all great resources.
I think that tube is very touchy as to it's position in the cavity it occupies, repair may be possible but I would try finding one first.

The Art Doctor wrote: These parts do not have a separate number and were part of a full kit that is of course NLA. Im thinking unless somebody has a pair of junk carbs with good tubes (if mine are cracked are any good?) I'm going to try and solder them. They are brass so it should work just a light swipe of flux and good silver solder should sweat it without
filling the tube in and clogging it shut. Any thoughts on this?

Hey Larry I know on the old Briggs and Stratton forum some of the guys have found metal brake tubing works well. I wonder if the whole copper tube could replaced.