1968 johnson 3hp questions?

i would first like to start off comending this forum for answering most of the questions i had, and some i didn't even think of. however, as it usually goes, the more you know, the more you realize you need to know...<br /><br />so, i just bought a boat with a 3 horse johnson motor, and have found out that it is a 1968 (s/n e2943980; m/n jw23m) what i can't pin down is, is it air cooled, and if so, i have seen some mention of impellers. if it is air cooled, what is the need for an impeller in the exhaust? how do i know if it has problems? there is no water indicator on this motor to tell me if water is moving through it or not. i know i need to get a manual for it, but i was hoping you all could point me in the right direction here.<br /><br />thanks in advance...

Re: 1968 johnson 3hp questions?

That is a great engine. Smooth as silk and economical.<br /><br />First off, it is WATER cooled. If you do not know the history of the impeller, install a new one.<br /><br />Water/exhaust exits, in a spray, through a series of holes about half way up the leg. Sometimes, those relief holes get plugged, run a toothpick through them.<br /><br />The engine should run on a 50:1 ration (fuel,to oil) Use only a TCW-3 rated oil mixed with six gallons of 87 octane unleaded. You can mix smaller amounts, just do the math.<br /><br />Also, use only Champion spark plugs.

Re: 1968 johnson 3hp questions?

dj-<br /><br />thanks for the quick reponse. i have noticed the hole you mentioned, but just assumed the spray coming out was water that filled the leg. i will certainly get and install a new impeller as soon as i can.<br /><br />i do love the motor. it doesn't care how slow i troll it, it just putters on for hours.