Logo
FULL SITE MENU

1971 Mercury 80hp 800 Ser No. 30522xx, 4 Cyl

L

Legge

New member
Engine sat in storage for 10 years. Checked all electrical devices and all ohm out in excellent condition, Rebuilt both Carburetors. Appears no obstructions in fuel supply. Removed gas cap from gas can after priming bulb to confirm venting. Engine starts, runs for 5 seconds, high idle, shuts down. Same on repeated starts. One tells me, "the problem is your lower Carburetor." Is there anything different between the two carbs or settings? Shop tells me, they are different carbs.
 
You have to help yourself put here. When it dies, and so regularly, you need to check IMMEDIATELY for spark. That will eliminate one half of the mystery.

Jeff

PS: My money's on a bad switch box.
 
I have checked for spark and have this on all four cylinders. Does anyone know where I can go to get a complete electrical breakdown on the switchbox. You have a good point.
 
Did fog all cylinders before starting, Did rebuild both carbs, Did change fuel pump diaphragm, all fuel lines and carbs no leaks and good gas supply.
 
1. Can someone explain the function of the "inlet and outlet check valves" on the fuel pump.
2. Disconnect fuel line from fuel pump. Squeezed fuel tank bulb with vent open, good supply of fuel on outlet side of pump. Turned engine over for ten seconds and no fuel from outlet side of pump. New gaskets and diaphragm installed. Could check valves be defective by hanging shut or closed?
 
Back
Top