Re: Mercury Model KG-4 Help
The KG4 is an awesome motor and NOT for the feint of heart on a light hull. It'll run circles around any other 7.5 out there, and will even eat modern 9.9s for lunch!
First off, let's figure out exactly what you have for a magneto. It should have a Phelon mag, in which case the coils, points and condensers are available and likely should be replaced. Not hard to do the wires while you're at it - use solid metallic core wire. Go easy on the starter ratchet - they tend to get chewed up when folks go crazy with a pipe wrench getting them off. A harmonic balancer puller and some grade 8 bolts should pop the flywheel.
There's an off chance you may have a Bendix-Scintilla magneto - the lesser of the two mags they used back then. Coils and condensers are available, but the points are not for these. Clean them best you can and reuse the. The coils are very pricey!
For the carb, make sure the float floats and that the carb flows fuel. If you choke it, pull it over and fuel dribbles fuel out the throat, it's flowing. Not much to rebuild on those as the float needle doesn't generally wear out on those gravity fed carbs. Just make sure it moves freely and isn't gummed up under the float. A modern plastic float can be adapted (Sierra part number 18-7208 available right here on i-boats) by boring out the center to fit the old style float needle.
For the prop - what style does your motor have? If you have a smooth-bore propshaft hole, there are lots of props out there for your motor. If it has a splined shaft, your choices are more limited.
Your motor is well worth the $50 you paid for it. I'd be hard pressed to let mine go for 10 times that! You can definitely put some time and money into it and not get hurt on it. Go for it - you'll love running it once you get it going well!
