spark and electric shift questions on my 40 hp johnson

[haulyard]

my johnson 40 hp model 4cesl69r has spark on bottom wire but no spark on top ,i checked the points and they are correct,does this motor only spark on both when a certain rpm is reached or do i have one spent coil???

And is there any way to check the electric shift by applying voltage to the wires that head down int the lower unit? i disconnected the wires under cowling and they have voltage when i use my selector switch(power to green for forward and power to other wire for reverse and no power to either when neutral is pressed)does motor need to be running to check them?
thanks

 

[HighTrim]

Re: spark and electric shift questions on my 40 hp johnson

In referenece to the spark, start with the coil, if it is original, it is likely shot.

In reference to the lu, I know diddly squat about them, but have learned a little from the experts such as Frank on this site. Hopefully they jump in here to guide you.

"With the switch not connected to anything, shift switch in neutral. Connect your Ohm meter lead to terminal "2". Ohm meter set to high ohms scale. Other meter lead connected to "N" or "R" should reveal NO reading if switch is the correct switch.

Disconnect the shift wires leading to the lower unit at the engine. Ohm reading on either shift wire to lower unit should be 8 ohms.

With wires still disconnected, set meter to read DC volts. Engine not running but with key ON with switch in neutral. There should absolutely no voltage reading at either wire.

Re-connect the shift wires. With either the "N" or "R" button pushed in, there should be a full 12 volt reading at either related wire. Anything less than 12 volts will not activate the electro magnetic shift coils in the lower unit."

Next check your lower unit oil. When was it last changed? Be sure to use only OMC/BRP Premium Blend oil.

Shifting still not working? Try connecting a jumper wire directly from the battery POS post to the green wire. Should go into neutral. Connect it to both green and blue at the same time. Should go into reverse. Does it?

If STILL no shift, the problem is in the lower unit. Likely candidate is the shifter piston stuck in the oil pump.

 

[tashasdaddy]

Re: spark and electric shift questions on my 40 hp johnson

Hydro Electric Shift)
(J. Reeves)

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 "Premium 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.