Starter Solenoid On 2002 Johnson 40HP 4 Stroke

[Mikee1]

Went to start our motor yesterday and it wouldn't crank. Heard the fuel pump operate and a click from the solenoid but no go. Measured battery voltage, 12.5V Measured voltage at starter motor while trying to crank, 0V. Measured on battery side of solenoid 12V. Very difficult to measure voltage to the solenoid coil so I felt the solenoid body while my wife turned the switch to the crank position. I felt and heard the solenoid operate so I decided the heavy duty solenoid contacts are worn out. I jumped the battery to starter contacts at the solenoid, the starter cranked and the motor started immediately. Let it run for 5 minutes at idle, showed a 15V charging voltage while running. Turned off the motor and tried a re-start. Starter cranked and the motor fired up. Tried a couple more times with no problem.
Question: Do I change the starter solenoid? It seems to me the battery voltage wasn't quite high enough to put sufficient pressure on the heavy solenoid contacts to cause a proper connection. (It is possible the battery was run down a bit if I had left my fish detector turned on 16 hours from when I parked the boat the previous night. However, I'm not sure I had left it on.)
Thanks,
Mike

 

[racerone]

Charge the battery and load test the battery.-----No beer tokens spent to do that.

 

[brodmann]

The starter solenoid is an electromagnet. It takes low amperage wiring to power coils inside the cylinder to create a magnet to draw a plunger up to make contact between the two larger contacts that handle the higher amperage draw that the starter needs to turn the starter. The solenoid is basically a switch. One of the large terminals has 12 volts all the time. It comes directly from the battery. The other large terminal goes directly to the starter. It only has voltage when the key is in the "start" position. The best test for the soleoid is to use a volt meter. Put the negative terminal to any good ground and the positive terminal to the starter side of the solenoid and have someone turn the key to "start". You should have at least 12 volts.

 

[Mikee1]

I think I used to much verbiage in my original post.
I did check with a voltmeter. 0 V on motor terminal with key in start position.
To summarize:
Motor wouldn't crank but solenoid clicked.

Jumped the battery to motor terminals at solenoid and starter zipped over and started the motor. Concluded the battery was well charged and starter motor OK. So must be solenoid.

After 5 mins of motor running/charging (15V charging voltage), shut off, retried and the starter motor cranked fine.
Do I replace the solenoid? $210 CDN.

 

[Crosbyman]

if you have not removed and cleaned all main power connections on the solenoid......battery starter etc... replacing the starter would not be my first step.

high current drain is needed by the starter and non-operation can be a simple current flow issue across oxydize surfaces.

Since you have no internal access to the solenoid contact surfaces... clean all external ones . battery cable crimps, solenoid bolts and surfaces and... starter cable surfaces and cable crimps .

 

[brodmann]

Your solenoid is "sticking" or your key switch is going bad. Straight full voltage "unstuck" the solenoid and after that they key switch and existing wiring was able to start the motor. I don't think it's a battery problem, but not sure Whether to replace key switch or solenoid. Next time it won't start, just take a screwdriver and use it to jump between the 2 smaller terminals. If the starter engages, then the key switch isn't making good connection. Either clean and reattached the wires at the key switch, or just replace the key switch.

 

[Crosbyman]

seems Motor wouldn't crank but solenoid clicked. I felt and heard the solenoid operate

so the switch itself should be ok no ?

 

[Mikee1]

The wiring connections under the motor cover look like the day they left the factory. No corrosion whatsoever. I think brodman has a very good point. The ignition switch is much more exposed to the elements and may have developed some resistance from corrosion. I've purchased a couple of wire piercing test probes and some liquid insulating tape and will measure the voltage across the control wires to the starter solenoid when the key is in the cranking position. If it's not essentially the battery voltage it would point to the ignition switch as the possible problem and I can investigate that further by removing it and jumping the contacts as brodman suggested.
Thanks for the advice and comments.
Mike

 

[Crosbyman]

if the solenoid clicks... the switch is ok imho

 

[Mikee1]

I will report back what I find. Will be a couple of weeks as my boat isn't close by.

 

[Mikee1]

I will report back what I find. Will be a couple of weeks as my boat isn't close by.

Problem was the starter solenoid. Although it was clicking it wasn't closing with enough force to properly close the heavy duty starter contacts. However, if the battery voltage was increased to around 13V it would manage to close the contacts with enough force to make the connection. I changed the solenoid today and all is operating well. I bench tested the new solenoid before installing and it operates below 8V.
Thanks for the help and suggestions.

 

[brodmann]

In the "good ol' day" when I was wrenching on old hot rods, you could actually take a soleoid apart. Basically there was a flat disc inside and the soleoid slid that disc in place to make contact between the two large contacts to send voltage to the starter. We would simply take that disc (about the size and thickness of a half-dollar) out and just flip it over and put it back in. The contact points on that disc would get burnt or simply worn down and the other side would be perfect. It was like brand new again. Now parts are all simply thrown away and replaced. Oh, those were good times!!