74 Johnson 50hp Starter/Solenoid Problems

[Chrisravosa36]

HI Im having problems with my motor again,I put on the starter solenoid, connected all the leads to the battery and the right spots on the solenoid. Tried testing the starter, nothing even worked, I had matched the wiring diagram in the factory manual, everything was correct. I took the old tester to it. I was getting 12v at the batt., I got 12v at the end of the battery cables attached to the ground and solenoid but through the solenoid I got nothing. When I attached it to the ground and then the starter I got .1v. Seems odd. I tried to test the starter next, I hooked up the positive fine, but there was no place to put the negative, so I tried a few things. I first tried the battery cable positive to the starter positive and the negative remained grounded on and exhaust plate bolt. no luck. Next I tried grounding it onto the starter holding it their, nothing. After that I tried holding it onto the little rod sticking out the top, nothing. I had the big red plug attached when doing this, and when I turned the key I got nothing. Guessing a new starter is needed? Maybe a solenoid as well?

Any Tips/help would be great to try to diagnose this issue? Put a lot into this motor and dont want to give up. Im not that great at wiring/electric work on motors, I understand some of the stuff but am not going to do anything else without some knowledgeable advice. THANKS!!!!!

 

[AlTn]

try youtube for testing a starter....I've helped test a few with the starter off the vehicle and a known good battery....starter on floor, foot on starter body cause it's gonna try to spin with some torque if it's good...+ jumper lead to positive post on starter and - lead to the ground strap stud...just touch the + lead for a second or two...you'll probably see some sparks and the starter should spin forcefully... do you have a starter, generator/alternator shop near you?..if so, they would probably test it for a small fee and could probably fix it for not much...I'd get an estimate first if you've never done business with them

 

[Chrisravosa36]

try youtube for testing a starter....I've helped test a few with the starter off the vehicle and a known good battery....starter on floor, foot on starter body cause it's gonna try to spin with some torque if it's good...+ jumper lead to positive post on starter and - lead to the ground strap stud...just touch the + lead for a second or two...you'll probably see some sparks and the starter should spin forcefully... do you have a starter, generator/alternator shop near you?..if so, they would probably test it for a small fee and could probably fix it for not much...I'd get an estimate first if you've never done business with them

Ive jsut got a new starter and solenoid, I brought the old starter to a repair shop and they said just get a new one. The one I had was the original and was not working. I recivied the new one today, tested the starter worked fine. I hooked everything up, turned they kay and got nothing. Im getting 12v going into thte solenoid, but nothing coming out to the starter. Im going to replace the fuse, which also was rusty. Would this effect the starting ability? Could it be a bad "big red plug" or some bad wires?

 

[hardwater fisherman]

Do you have some sort of safety switch? It is meant to prevent starting if in gear and or if the throttle is too far advanced. If defective you will have no current to the starter.

 

[Chrisravosa36]

Do you have some sort of safety switch? It is meant to prevent starting if in gear and or if the throttle is too far advanced. If defective you will have no current to the starter.

Im not sure. When I am testing this, I have the carbs off, and the timer base is set at idle. also the shift connecter is off.

 

[natemeins]

Look for a safety interlock switch on the throttle control linkage on the motor. This will not be on the carbs, but tucked behind or inboard of the large lever. This prevents you from starting the motor in the event the throttle is set at a high setting. When the throttle is at idle to the first detent, this switch provides a ground to the relay coil and when you hit the starter switch you add the 12VDC to the other side of the coil, closing the relay to apply 12VDC to the starter. If the throttle is above the first detent or the switch is dirty, it will not provide the ground necessary for the relay to work. For troubleshooting purposes, find the wire from one of the small terminals on the relay to this switch, remove it from the switch, and attach it to a good ground. Give the starter a try again. If it works you've either got a bad switch, a dirty switch (it can be disassembled and cleaned), or your throttle cable is out of adjustment.

 

[Chrisravosa36]

Look for a safety interlock switch on the throttle control linkage on the motor. This will not be on the carbs, but tucked behind or inboard of the large lever. This prevents you from starting the motor in the event the throttle is set at a high setting. When the throttle is at idle to the first detent, this switch provides a ground to the relay coil and when you hit the starter switch you add the 12VDC to the other side of the coil, closing the relay to apply 12VDC to the starter. If the throttle is above the first detent or the switch is dirty, it will not provide the ground necessary for the relay to work. For troubleshooting purposes, find the wire from one of the small terminals on the relay to this switch, remove it from the switch, and attach it to a good ground. Give the starter a try again. If it works you've either got a bad switch, a dirty switch (it can be disassembled and cleaned), or your throttle cable is out of adjustment.

I cant find this, can you spot it? I bought some new fuses, 15amp. Il try those today and see if those make any change.

 

[natemeins]

No Title

Well you're looking in the right place. Looks like the boss is there for the mount screw. Mine is a '71 Lark 50, I thought they'd be similar. I've attached photos of mine.

 

[F_R]

A 1974 50hp does not have a safety switch on the throttle at the motor. It does have a neutral start safety switch in the remote control. I gotta ask--did you install the correct solenoid, or a look-alike car solenoid. If a car solenoid, throw it away and get the correct one. There IS a difference and a car solenoid won't work!!

Then quit guessing. You seem to have a voltmeter. Check the voltage at the small (ungrounded) terminal on the solenoid while somebody turns the key to start. Should show 12V and solenoid should click when key it turned. If not, the fault is somewhere between the battery and fuse or between the fuse and key switch or between the key switch back to the solenoid (and yes the big red plug matters) OR the battery to engine ground connections. OR right at the battery terminals. Did you take them off and clean them up shiny bright?

 

[Chrisravosa36]

A 1974 50hp does not have a safety switch on the throttle at the motor. It does have a neutral start safety switch in the remote control. I gotta ask--did you install the correct solenoid, or a look-alike car solenoid. If a car solenoid, throw it away and get the correct one. There IS a difference and a car solenoid won't work!!

Then quit guessing. You seem to have a voltmeter. Check the voltage at the small (ungrounded) terminal on the solenoid while somebody turns the key to start. Should show 12V and solenoid should click when key it turned. If not, the fault is somewhere between the battery and fuse or between the fuse and key switch or between the key switch back to the solenoid (and yes the big red plug matters) OR the battery to engine ground connections. OR right at the battery terminals. Did you take them off and clean them up shiny bright?

F_R, I ordered another solenoid, I got this one at at auto parts store and they convinced me that it would work..(got me hook line and sinker) I did check the voltage with the grounded and the solenoid to starter cable, I got nothing with the kay fully turned. For the "Big red plug" I got one off ebay, and it fits fine, it has the key switch at the end, with the push to choke and buzzer alarm thing. It does have a yellow with red dashes wire that is clipper off at the end near the key )Il get pics tomm) I hear no click when the key is turned. I did not clean the terminals shiney bright yet, but will do that tomm! I got a new 20AMP fuse, It is too long, but touches in both ends fine, need to get the right one soon. Also, when you mentioned checking the voltage on the small ungrounded terminal, you are talking about the top small terminal with the tanish wire right? Thank you for the response!

*Also I am using one of the shipmaster controls (no electrics at all) so will this affect anything?

This is the Solenoid I ordered on amazon: Caltric STARTER RELAY Solenoid Fits OMC JOHNSON 50 50HP 1971-2005

 

[F_R]

Well, that's some new and interesting interesting information. Now I don't know what you have for wiring. But traditionally, the yellow/red wire is the start wire. I don't know how it is matching up with the engine side plug. Yes, I was talking about the "tanish" wire. Actually, in an earlier life, it was white. But they discolor with age.

I suppose you are going to have to trace out the wires at the switch to see what's what.

Regardless of colors, what is required is:

The fuse leads to the BAT terminal on the key switch, traditionally red/purple striped
The START terminal on the key switch leads back to the small terminal on the solenoid. yelow/red OR white.
The Black/Yellow is the kill wire--goes to one of the M terminals
Other M terminal is grounded
Purple/White stripe wire is Choke
Probably will be some purple wires on the "A" terminal
Grey wire is tachometer
Do not, under any circumstances allow a voltage-carrying wire touch the black/yellow one. An expensive mistake that will destroy the Power Pack

You will have some electrical circuit experience by the time you figure this one out.

 

[Chrisravosa36]

Well, that's some new and interesting interesting information. Now I don't know what you have for wiring. But traditionally, the yellow/red wire is the start wire.

In the serive factory manual kit I have right now, it shows nothing with a red/yellow stripped wire. So in re you saying the wiring on the motor could be bad? or the wiring of the switch? I will get some pictures of the setup I have on the motor in a little bit.

 

[Chrisravosa36]

I GOT IT! no need to be a circuit master (yet)! I went in the shop this morning, stared at it and saw that the clipped wire was supposed to go onto one of the terminals of key switch! The wire wasnt really long enough, but it worked. hooked it up, turned the key and the starter went off. A charged battery. 12.4v Interstates big battery cranked slowly. (with a new starter) Im not sure what is happening with this, tried a diff battery with the same results. What could this be? A weak starter? not sure. Also for the red and yellow wire can I use any wire to extend that, or does it have to be a certain kind (dumb question, but idk:faint2 I know these OMC motors when they crank up, and it doesn't sound quick enough.

 

[F_R]

Any wire as long as it is the same wire diameter (or larger) will work for your extension. Do you know how to make voltage drop tests? Doing so would be appropriate in diagnosing your slow crank condition. Any high amperage connection or cable between battery / solenoid / ground return would be suspect. In other words the big battery cables circuit. The little wires to the switch and back do not carry high amperage.

 

[Chrisravosa36]

Any wire as long as it is the same wire diameter (or larger) will work for your extension. Do you know how to make voltage drop tests? Doing so would be appropriate in diagnosing your slow crank condition. Any high amperage connection or cable between battery / solenoid / ground return would be suspect. In other words the big battery cables circuit. The little wires to the switch and back do not carry high amperage.

Ok thanks for the advice, I just extened the wire. For the cranking I thin kit was just the coroded terminals. I took everything apart, cleaned the terminals, connections and studs of the starter, solenoid and battery, put it back together and it cranked over just fine! Thank you for your help! Il be able to get her running this week if shes go spark in her!