72 johnson 50hp stuck in forward

[bluebrownie]

start it up, it is in forward...prop moving...in neutral and reverse, still in forward... checked the swith in the control box...power ok...checked control box to engine...power...then took lower unit off... power to solenoid ok... and it was engaging as we tried it when the solenoid was out ... put it back together... started up the motor... shifted into forward, reverse and neutral as it should... last week....today...started it up...same thing again...all forward... any ideas...? bad solenoid??? going on the annual boys fishing trip next weekend.... i guess i have forward.... and a paddle for reverse... but having the prop always in forward is a problem... any ideas?

 

[rickdb1boat]

Re: 72 johnson 50hp stuck in forward

Can't be sure, but it does sound like the selenoid. Bout the only thing you can do is verify you are getting voltage to it and if so, that would narrow it down. Could be a bad connection too. Check the wiring first from the control to the engine..

 

[HighTrim]

Re: 72 johnson 50hp stuck in forward

Im not experienced with those lowers, but have learned a little from those on this forum that are, and they are where this info is from. FR or Joe are the guys you want to troubleshoot this.

Disconnect switch from everything. Shift switch in neutral. Connect your ohm meter (set to HI ohms scale) lead to terminal 2. Connect your other meter lead to "N" or "R". It should reveal NO reading if switch is correct.

Now, 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.

 

[bluebrownie]

Re: 72 johnson 50hp stuck in forward

is ther a fuse that could be causing this problem?

 

[F_R]

Re: 72 johnson 50hp stuck in forward

Those push button switches are notorious for being intermittant. Do as High Trim said, check it out electrically. And don't be worrying about the solenoids--the least likely problem. I would do the test is a slightly different order though. First, slide the insulator sleeves back from the connectors by the powerhead where the wires go down into the lower unit. With wires still connected, check voltage on green wire when neutral button is pushed. Should be battery voltage (12v). Then do the same thing with reverse--should be 12v on BOTH green and blue. Repeat test a whole bunch of times to make sure it works every time. If it passes the test every time, the switch, cables, fuse, and everything else ahead of there is OK.

If all that passes the test, check your lower unit oil. Change it if it hasn't been done lately. Use only OMC/BRP Premium Blend oil.

If STILL no shift, connect a jumper wire directly from the battery + post to the green wire. Should go into neutral. Connect it to both green and blue at the same time. Should go into reverse.

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

Remember, with all these instructions, the motor has to be running before it will shift. It won't do anything just standing still.

 

[bluebrownie]

Re: 72 johnson 50hp stuck in forward

when you say "push button switches" what do you mean... the shifter on the control box... i don't have buttons, but a shift arm...forward neutral reverse...?

 

[tashasdaddy]

Re: 72 johnson 50hp stuck in forward

you have a switch in the controller, it has a lever on it that actives the lower unit. evinrude has buttons.

 

[F_R]

Re: 72 johnson 50hp stuck in forward

Yeah, being an old Evinrude guy, I had push buttons on the brain. Johnson does the same thing with a different type of switch. Result is the same.

 

[bluebrownie]

Re: 72 johnson 50hp stuck in forward

ok...so let's see if i got it... if i check the voltage on the connecters by the power head...and i sometimes get voltage and other times not... then i can assume it is the switch...as you call it... what is the name of the part that would be replaced....? i have the parts manual for this... but not sure what the "switch is"... also as i check this, does the motor need to be running... or just the switch in the ON position? tx again... iam a newbie... trying to figure thsi stuff out...

 

[F_R]

Re: 72 johnson 50hp stuck in forward

There is a switch inside the remote control that is actuated by moving the control lever through forward/neutral/reverse positions. That is the switch that sends voltages to the wires by the powerhead and ultimately to the solenoids in the lower unit. It is called a "switch and cable assy" in the parts book. The part number that I see is 385253.

The key has to be turned on to check the voltages, but it does not have to be running. However, it won't actually shift unless it is running. But the voltages will be present.

May I clarify one thing? If the voltages are consistently OK, then the switch and wiring is OK. If the voltages are inconstent or sometimes yes, sometimes no, it probably is the switch. But a loose or damaged wire somewhere could also cause erratic behavior.

 

[robtown]

Re: 72 johnson 50hp stuck in forward

There is a 3way switch inside your controls that controls the voltage to your lower unit. When there is no voltage sent to the lower unit, your motor is in forward gear. Voltage to one of the other wires will put it in neutral or reverse.

These old Johnson control boxes are notorious for that 3-way switch going bad. The 3-way switch that goes bad on these hydro-electric control boxes is a discontinued part, so it's next to impossible to find a replacement.

 

[bluebrownie]

Re: 72 johnson 50hp stuck in forward

ok... so i put a jumper on the pos. + terminal and ran it to the green... prop was still in FORWARD...not neutral... then i connected the jumper to both the blue and green... NO reverse... i called the local marine shop...they said that 90 % of time it is crud, junk, in the pump and plunger in lower unit... wouild this jumper experinment essentially lead me to this conclusion? and if so... this means taking LU off, cleaning the solenoid chamber???? or what else... and how to do that?
tx ...got a trip next week and am in the midst of these problems...and no shop can get me in...

 

[bluebrownie]

Re: 72 johnson 50hp stuck in forward

anyone?

 

[rodbolt]

Re: 72 johnson 50hp stuck in forward

if the voltages are consistant and the solinoinds test good you may have a nick in the wire harness from the powerhead to the solinoids, no good way to repair other than replace, you may also have the wrong gearcase oil. you may have a clogged pump screen in the lower or the shift piston oring is bad.
nice thing about Hydro electric over the hydro mechanical is its way easier to reassemble the case
last seal kit I bought did not contain the shift piston oring, had to be purchased seperately.

 

[F_R]

Re: 72 johnson 50hp stuck in forward

ok... so i put a jumper on the pos. + terminal and ran it to the green... prop was still in FORWARD...not neutral... then i connected the jumper to both the blue and green... NO reverse... i called the local marine shop...they said that 90 % of time it is crud, junk, in the pump and plunger in lower unit... wouild this jumper experinment essentially lead me to this conclusion? and if so... this means taking LU off, cleaning the solenoid chamber???? or what else... and how to do that?
tx ...got a trip next week and am in the midst of these problems...and no shop can get me in...

To sum it all up: If using the jumpers like you just indicated did not cause it to shift while running, there are only two conclusions. One, the wire going down to the lower unit may be bad, or Two the problem is in the lower unit. #2 can be broken down into two more conclusions: One, it could be the solenoids, or two it is a problem with the oil pump/shifting piston assembly.

The solenoids are servicable by removing the lower unit. But the oil pump is the last thing to come out of the case when completely disassembling and the first thing to go back in. A major operation to say the least.

Only further inspection can tell the story.

 

[robtown]

Re: 72 johnson 50hp stuck in forward

I had the same issue with my 72 Johnson 50 hp. Turned out that something in the lower unit was to blame (crud, oil pump, etc...). I had a hard time finding anybody willing to work on it, when I finally did he quoted 350.00 just to teart down and look at it then we'd discuss what it would take to fix it, and it would take about 6 weeks till he could get around to it.

I bought a used lower unit (actually it came off an evinrude) off ebay for 200.00 plus shipping. I'm going on my third summer with this project boat. I just took it out yesterday for the first run of 2008.

 

[bluebrownie]

Re: 72 johnson 50hp stuck in forward

Problem solved.... the solenoids., green and blue...connections at the power head were not particularly clean...sanded them up good, greased them and voila... problem sovled...shifting as it should. thanks to evereyone who offered your input...it was helpful and a learning process... tx again.

 

[Benny1963]

Re: 72 johnson 50hp stuck in forward

by the way i have a good 72 lower with prop if ya need it in the future [cheap]
also have a good set controls yellow plug cheap[dont need them any more .]
sold my 50 and 65
good luck they are good motors

bennyb