Logo

19721975 65hp Johnson lower unit question

J

JETalley

Guest
I just aqquired this motor an

I just aqquired this motor and it seems like I am losing reverse. Forward works great but reverse is barely moving the boat. I cant feel it engage and am wondering if this is easily fixable or not. Any help would be greatly appreciated.

TIA JT
 
"JETalley.... That engine has

"JETalley.... That engine has a shift setup as follows. This info should help you in your troubleshooting.

(Hydro Electric Shift)

The shifting setup of the lower unit is what's called a "Hydro Electric Shift", which is quite complex consisting of voltage being applied to solenoids in the lower unit which in turn change oil passages via a oil pump that supplies various pressure on a spring loaded shifter dog.

The wires leading to the lower unit (at the powerhead) are "Green" and "Blue". The engine must be running or cranking over in order to shift out of forward gear.

You CAN NOT use HI VIS lube in that lower unit. You MUST USE what OMC calls "Preminum Blend" lube, commonly called "Type C". (A thinner lube)

In neutral, you need 12v to the "Green" wire.
In reverse, you need 12v to both wires, the "Green" one and the "Blue" one.
In forward, there should be no voltage to either wire. (The spring loaded shifter dog forces the unit into forward gear)

To check the lower unit for proper shifting to make sure you have no trouble there, remove the spark plugs to avoid problems and to allow a higher cranking speed.

This next step eliminates the actual shift switch in case problems may exist there.... Disconnect the blue & green wires at the knife connectors (the rubber insulated boots) leading to the lower unit at the powerhead, then using jumpers, take voltage direct from the starter solenoid to apply voltage to the "Green" wire for neutral, then both wires 'Green" & "Blue" for reverse (Remember the engine must be cranking over in order to shift).

With no voltage applied, the unit should be in forward. No need for a ground jumper... the lower unit's already grounded. You may crank the engine with the key switch or by energizing the starter solenoid with a jumper wire.

Joe
"
 
" Thank you for your help with

" Thank you for your help with this. I will try the steps you suggested. Also with reverse, I hear a clicking noise in the lower unit area when I put it in reverse. Does this mean anything, or could it still be electrical.

On another subject, it seems this motor only runs at high speeds when it wants to. What I mean by this is, sometimes it will just take off when i give it full throttle (with a little hesitation) and sometimes it just will not take off at all. When this happens it will not do more than 2500rpms but will sputter like it is trying to pick up and go but does not until it is good and ready to. Sometimes I feel like it is fuel related and sometimes I think it is electrical or something. It will always rev up to 5000+ rpms in neutral but not forward. If I leave it going long enough it will pick up and go great. 4000+ rpms in forward. I would really like to get it turning at least 5000 rpms at least. Is there a way to adjust something for this? Thank you again for any help.

JETalley "
 
Motors have no trouble runnin

Motors have no trouble running at 5000rpm in nuetral when there is no load. It may result in destruction of the motor. Do a compression test to check condition of the cylinders and clean the carburetors and the brass high speed jets.You could also try to open the low speed jets to get better acceleration.Check the spark on EACH CYLINDER and make sure that it will jump a gap of 7/16".
 
" had a 75 with electric shift

" had a 75 with electric shift.
It too would refuse to run fast, then gradually pick up and go just as well as normal.
Problem was weird. Halfway down the leg is a little plate where the wires go through the exhaust pipe on their way to the gearbox. This worked loose and was allowing the exhaust gas to find its way into the motor cowling. Engine was trying to run while breathing its own exhaust. If you could get the boat on the plane, the exhaust would then be sucked away by the water rushing past the exhaust outlet, and the boat would run fine. Try running engine with the cowling off while the boat is on the water. "
 
Silly question maybe... but i

Silly question maybe... but is the cowling the molding under the head? And is this easy to remove? Thanks

Jtalley
 
" I have a 65 Johnson out brd.

" I have a 65 Johnson out brd.When sitting idle running she does very well. When load applied and ready to go, she dies right out and stops.Now I'm hearing a missing noise. What direction should I go?
Just had a lot of work done on carb and cleaned and stuff .. "
 
Back
Top