1977 Mustang

functional and dependable ,yes. safe, no. you need to have at the minimum a marine alt, starter, dizzy, fuel pump, blower and carb for fume protection. you can find most of the stuff pretty cheap used and new marine holley carbs are pretty abundant on ebay.

it sounds like it is good shape, but i would not even guess at a price. congrats that is still a marine motor. thats good.

i don't want to use all keiths hard drive space, but check for fuel and spark.

toadys fuel isn't the greatest quality. over the winter, the gas will evaporate from the bowl and clog it up. it is possible for the float to get hung and not allow fuel into the carb or flood the whole boat. marine carbs have a 'puke' tube that will flood and kill the motor if the float gets hung in the open position.

see if you have a spark with a timing light or the old screwdriver stuck in the spark plug wire trick. if she sparks, throw a half a shot glass of fuel down the carb and turn the key.

if she does not spark, check the points. they should have about a credit card width openning at the top of the lobe. make sure the inside of the cap is dry and corrosion free.

if the points look okay, check the ballast resistor. the ballast resistor is mounted on the bell housing. (it is a white 1/2" x 1/2" x 3" rectangular box.) you should have 12 or so volts to ground on one side with the key on and 7 to 9 volts on the other. if you have nothing, check the main wiring plug in the same proximity for green fuzz or it could be the key switch. sometimes when the starter is engaged there is not enough voltage to get ignition, but we can get to that later.   

a brass freeze plug set is less than 10 bucks, but don't consumate the deal until you are sure the motor is in decent shape.

if the the engine has been subject to freezing temperature with plain water in the block or manifolds, it could have a crack somewhere. small cracks may not reveal themselves until the engine is up to operating temperature.

tell the guy you want to look at the carb and get it running before you finalize the deal. if the engine is flooded, you should smell fuel at the exhaust pipes. hold it wide open while you turn it over for ten seconds and smell the exhaust. a little tap with a handle of a screwdriver might dislodge the float in the carb if it is hung. if you don't smell fuel, try the shot glass of fuel.

find a letter and a number on the castings. c is for the 60's ie C8 would be 1968. D2 would be 1972 ect. none of the casting marks will tell you if it is a marine motor as far as i know.

see if the prop has a 'R' or an 'L'.

you willl need a new impeller for the raw water pump before you hit the water or run the boat for any extended period. you will need the # and make off the pump. sherwood or jabsco.

freeze plugs are just holes in the block to remove the sand after the casting process. that is a misnomer. they do sell a temporary rubber plug at most auto parts stores.

the reference section here will get you going. download it and print it out.

Through a little internet research I think i have answered my question. The impeller should be replaced because it deteriorates over time. Is this correct?

Thanks for your help. I believe that is all for now. I will keep you updated on the status of the trade/purchase.