The rubber diaphragm in the fuel pump is one of those things that tends to last forever until it gets dry. Then it doesn't last long after that. Happens with mechanical pumps on cars too. They are fine for a long time as long as they stay wet, then you let them sit and it siphons back and you get sudden death.
I will second the need for a vented tank on Mercs. If I forget to vent my plastic tank on the M70, I'll take off up the lake and it dies and my tank looks like it was run over with a car.
The gaskets for the fuel pump showed up Saturday, so Sunday, after making the wife breakfast, I went to work. Nowhere is it written there are 2 yes 2 fuel pumps on this thing. Everything is plumbed so it can run on 1 pump but I need to get another set of gaskets to redo the other pump. While I was in there I noticed all the wires looked like crud, so I went ahead and re wired the thing so I do not have to worry about short circuits. Also installed the new pitot tube and hose.
The second set of gaskets arrived and I took the time to replace them. When trying to pump up the fuel line it got hard to squeeze bt not firm like leaky brakes. Go back to the motor and sure enough on of the fuel lines is leaking. I am going to make a hose barb adaptor so I can use the existing elbow and compression fitting. pictures to follow.
As foretold here is a pic of the fitting. New part on the bottom.
One of the nice things about older outboards is that their fuel pumps generate their own lift once you prime them. When re-plumbing things, you only really need to worry about modest pressures at any fitting. Anything before the motor is either in vacuum or the modest pressure of a hot portable tank. I ran a 25hp Merc outboard for about 15 years without a clamp on the hose at the tank fitting. I ran it all summer without realizing I forgot the clamp. For the next 15-ish years I just let it go. One really hot day it pushed the hose off, so I fixed that with a zip tie.
I realize that the fuel system is low pressure. Just enough to pull the fuel up(vacuum) and move to the float bowls. I just do not want a Viking funeral.
In reply to zordak :
Might be your last chance for a smoking hot body.
In reply to Curtis73 (Forum Supporter) :
Ba dum. Tissssssh. Truth, my only chance.
I took the boat out Saturday, it still does not like extended periods on full throttle. I am going to get gaskets and fuel filters for the carbs, if I can still get new filters. If not clean the old ones. The tank is a newer plastic with a newer fuel hose. Although I am going to try out the original steel tank that came with the boat. 6 gallons does not go far enough.
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