1972 Merc 50hp fuel pump

[KevinF]

I have a 1972 Merc 500, 50hp that seems to be having a fuel problem. I have taken the carbs off and cleaned them and inspected the diaphrams in the fuel pump. Cannot get it to start. If I prime the cyclinders with starting fluid it will start and run for a few moments. Here is the question. Should fuel be pumping through the pump when the engine turns over or only when it is running?<br /><br />Thanks !<br /><br />Kevin

 

[Laddies]

Re: 1972 Merc 50hp fuel pump

It should pump some fuel when turned with the starter, Don't use starter fluid it can ruin your engine, use gas and oil mix out of a squirt can

 

[Chinewalker]

Re: 1972 Merc 50hp fuel pump

Was there gas in the carbs when you removed them? If you were to remove the brass hex plugs underneath the carb mouth does gas drool out? Are the hoses for the pump routed properly?<br /><br />Methodically work your way front to back through the system and keep eliminating what it isn't... Fuel to connector? Fuel to pumps? Fuel through pumps? Fuel to both carbs? Fuel through carbs? Fuel into motor? Just verify each and you'll eventually localize the issue rather than taking pot shots at various theories... <br /><br />- Scott