Post by pontoongirl on Oct 17, 2010 12:19:21 GMT -1
HI, I have a 1971 50 hp Johnson motor and this year it lunging forward when starting in neutral. It will go forward if not tied to the dock. Also, I am keeping the boat at home this year to save money, we have drained the lower unit oil, is there any thing else we should do?
Sounds like the linkage between the throttle/shift cam and the lower end needs adjustment. It's tricky. You might want to invest in a service manual or take it to a mechanic. Sounds dangerous. Be careful (as always). If you are putting it up for the winter....Make sure no water is in the cooling system. This usually done by tipping the motor up and down as far as it will permit. Empty the fuel tank and store.
Last Edit: Oct 17, 2010 14:40:07 GMT -1 by tinker1
When tempted to fight fire with fire, remember that the Fire Department usually uses water.
I know this is a little late of a reply, but in case you are still reading, here goes.
That motor is a hydro-electric shift. Johnson/Evinrude used that particular method in '71-'72, following the plain electric shift in '62 - '70. Instead of having a shift cable like a conventional shifting outboard, that motor will have a switch in the throttle handle, and set of solenoids controlling the hydraulic shift pump in the gearcase. However, these solenoids don't last forever, and unfortunately, are no longer made, so once they go, the motor isn't easily repairable.
The solenoids default to forward, as a fail safe, so if they die, you can still limp home. Probably the only intelligent thing OMC did with their gearcases in that time, as the electric shift idea, with the technology available at that time, sure wasn't a success. What you are seeing is the solenoid not triggering into neutral. It could be the solenoids going bad, or it could be the switch in the throttle handle going bad. A search of google should yield the test procedure to evaluate the solenoids condition.
On the gear lube, drain and refill it before winter. Leaving it empty is very bad. However, those hydro-electric shift gearcases use a different fluid than most engines, so you are going to need to order the correct fluid off the web, or possibly buy it from a Johnson/Evinrude parts center, as it isn't the standard API GL-5 lube all the rest of the engines use. What you need is what used to be called Type-C, and I believe it is currently called OMC Premium Blend.