Joe Reeves, Hydro-electric shift question

[jonb_in_MN]

I am a new first time boat owner.<br />My '71 Johnson 50 hp starts great and runs smooth.<br />But won't shift into Reverse...always in forward.<br /><br />The Hydro-Electric Gearcase, I understand needs a special type C gearcase oil. The dark black thick oil I drained out of my gearcase smelled strong, I figure it's 80-90 weight. the Previous owner must not have known what gear lube to put in? I put in the correct OMC Premium gearcase oil last night. I test drove the boat and same problem.. No reverse<br /><br />I figure the thick oil gummed everything up. another post on this site suggested putting pre-mix (I assume Gas/oil) in gearcase and rotating the prop alot. Is this a smart idea? or is it time to tear the lower unit apart?<br /><br />Do you think that 80-90 oil did any physical damage to the lower unit parts?<br /><br />any input is appreciated<br />Jon

 

[Joe Reeves]

Re: Joe Reeves, Hydro-electric shift question

Jon..... Before tearing into the lower unit, find the two wires (at the engine) that lead to the lower unit. There will be a color coded "Green" wire and a "Blue" wire.<br /><br />No, I don't think it's a good idea to wash out the unit with gasoline etc. Simply draining the unit and refilling it with the proper lube would correct the lube problem.<br /><br />The follow test can be performed at cranking speed with the spark plugs removed. Besides using the solenoid as a 12 volt source for the following test, you can also use another small jumper from the battery side of the solenoid to one of the small 3/8" hex nut terminals of the solenoid (not the gound nut) to crank the engine.<br /><br />Disconnect the knife connectors you'll find there so that the wires are connected to nothing. Now, run a small jumper from a reliable 12 volt source (the battery side of the starter solenoid will do) to those lower unit wires as follows:<br /><br />12 volts to the "Green" wire, while cranking, should give you neutral.<br /><br />12 volts to both the "Green" and "Blue" wire at the same time, while cranking, should give you reverse.<br /><br />No voltage to either wire while cranking should give you forward.<br /><br />If the above test gives you the proper shifting sequence, the lower unit is okay and the problem would be elsewhere (the shift switch, wiring, whatever). If you still do not have reverse, then it's time to drop the lower unit and inspect the shift wiring cable first, then unfortunately, the internal components.