72 model mercury 500 50hp

Ive got a 72 model merc 50hp and i need the carb rebuilt on it and wen i baught the boat i was told that the motor ran fine until u lowered it into the water then it wuld die, and the guy thought the float was sticking. what it comes down to is im not real familiaR ON MERC OUTBOARDS and i feel dumb saying it but i didnt even see what looked like a carb on it wen i took the cowling off? and also what kind of fuel tank set up shuld i use on this motor?

Re: 72 model mercury 500 50hp

I was an OMC guy at the time, but here is a SWAG.

The 50 hp was based upon the original 4 cylinder Merc design which had 2 carbs right at the front of the engine with the conventional bowl, side linkages, and all. I think they were Tillotson brand. If you had the cowl off, the only reason you wouldn't see them would be if there was an "air box" covering them. I know Merc used airboxes later on (and still do), but don't know when that engine got it's. The box is a black plastic hootus covering the carbs which can easily be removed.

The industry was running 50:1 fuel-oil ratios then which was 1 pint of oil to a 6 gallon tank of gas.

The engine had a fuel pump so all you needed was a single fuel line with a squeeze bulb which allowed you to prime the carburetors prior to starting......you squeezed the bulb several times till it felt good and firm.

I don't understand the part about engine position, but installing carb kits probably would not be a bad idea and a good cleanup of the carb (varnish removal) would surely be in order.

Mark

Re: 72 model mercury 500 50hp

Definitely you need a manual, then remove the carbs for thorough cleaning in a solvent. Purchase replacement parts for the carb and re-install.

Alex