1964 mercury 50hp thunderbolt outboard Help

[mike14837]

Hi i was wondering if anyone could tell me if there is a pee hole on a 64 mercury 500 thunderbolt, and if there is where its at. Motor seems to run cool but motor isn't pee in. thank you

[bigsprings]

The tell tale hole should be on the lower pan near the back of the motor. If you take the faceplate and wrap off you should be able to trace the telltale hose down to the bottom of the pan from the water jacket( left side of powerhead).I would first reccommend checking the telltale hose for obstructions, they are notorious for getting a mud wasp or spider nest in them. Secondly, your impeller is a wear item and should be replaced as part of a regular maintenance schedule. Dry worn and cracked water pump impellers can dislodge and travel through and lodge in the passages of your cooling system. This prevents a problem since now you have to pull the water jacket and exhaust baffle from your 46 yeat old motor. Expect to break at least half of the 1/4 20 bolts, unless you carefully heat everything up with mapp gas. Good news though, That is a nice old motor and parts are readily available, even at NAPA, if you will accept aftermarket Sierra. I would suggest purchasing the 1965 and Prior Service manual from Mercury... or used. Stay away from the Seloc and others.Good Luck , Jason

[Trap Jaw]

I will agree with Springs on one thing. If you don't know how old the impeller is change it. It is a major P.I.T.A. but much simpler then the alternative.

If you clean out the overflow tube and there is still nothing coming out. Take a blow gun and shoot compressed air in it. More then once that has been the only problem I've had. Probably still just bugs, but a lot simpler then pulling the lower unit, installing a new impeller and then finding out there is still no water coming out the overflow.

I will disagree with Springs on one thing. I have never found NAPA to be a reliable source for parts for Mercs. Evinrude/Johnson parts are available through NAPA, and CHEEP to boot. Merc is like Apple Computers, they keep everything in house. As a result they know they've got you. So bend over and grab your ankles. They made one heck of a motor, they run like a raped ape and reliable, but if you need to service them it can be costly.