Mariner 1999 Solenoid (?) Issue

[Tightlines72]

Hey folks,
Relatively recently I purchased a 1999 Mariner 90 hp 2 stroke. I've taken it out quite a few times with no major issues to speak of. For the last month, the boat has been sitting on the trailer while I repaint the deck. To keep the boat in running order (or so I thought), I have been running the engine with muffs every time that I go out to do work on the deck. It was taking a few cranks to turn over but I assumed that this was because I hadn't run it in a while, and after a few (or more) attempts it would start up and idle well every time. However, as soon as I finished the deck and dropped her in the water, I couldn't get the engine to turn over. After putting her back on the trailer, taking the cowling off, and trying again all that I got was a single loud click when I tried to crank her up. Naturally, I came here and started reading about the ignition process and thought that I had the problem narrowed down to dirty or incomplete connections between battery, solenoid, or starter. I have tried two different batteries, one brand new, and both fully charged. Today, I changed out the lugs on my battery cables, cleaned the battery to solenoid connection, solenoid to starter connection, and all of the ground connections as well. After doing so, upon cranking I was only hearing the click about 1 of 5 cranks otherwise there was nothing at all. I felt the solenoid body and it was hot to the touch but the starter was cool. Does anyone have a potential diagnosis for what my problem might be? Do I need a new solenoid? A new starter? I'm also curious about why the work I did today would have made the click stop. My iboat reference told me to measure the voltage at the "starter terminal to battery ground with the starter engaged" but I have to admit that I'm not sure how to manually engage the starter. Any info you guys have would be hugely appreciated as I'm trying to get back on the water ASAP.

This was the thread I used for the majority of my information http://www.iboats.com/basics/diagnos..._problems.html

New boat owner here, so don't make fun of me too much

 

[wrench 3]

It looks like a really good thread that you are using for reference. By "with the starer engaged" they just mean to turn the key to the start position. But remember that for this test to be valid the solenoid must click. If it doesn't, then you will need to go down to the next section on the chart.
If you have been trying to get it to crank for quite a long time it is normal for the solenoid to be hot.
Run the tests and see what happens.

 

[Texasmark]

First of all there are 2 circuits in the solenoid. One is the low current energizing circuit and the other the high current starting circuit.

The low voltage circuit gets 12v from the key ignition switch in the START position to one of the small terminals on the solenoid. The other has to be connected to the same electrical circuit (engine block connection usually) that attaches to the battery - terminal...aka "ground". Upon applying 12v the solenoid energizes, pulling the high current plunger (within the solenoid) down to connect to the input and output ⅜" stud plates and supply power to the starter. The "click" you hear is that plunger slamming into the plates and making connection.

If you have and know how to operate a voltmeter (DMM, DVM, Analog volt meter) it's quick troubleshooting:

No click: Voltmeter across 2 small terminals on solenoid. Key to START. 12v (battery voltage) on meter. Should be good to go! Voltage low and no click: Indicates a shorted energizing coil within the solenoid and could cause excessive heating of the solenoid. Also, no voltage on output hight current stud to starter. Second option is that the shaft is binding within and can't move when energizing force applied....but this does not overheat solenoid and voltage is good across the terminals. Third option welded contacts.........new solenoid required in any case. I boats sells them; look at the top of this page.

That's about it since you said "now no click".

Assuming that the coil is ok as is the shaft and the lack of a click is caused by the high current contacts themselves due to pitting, an old age problem. A couple of things could be the result of pitting:

Welded high current contacts: Plunger could remain down within the solenoid such that it is already a closed switch so energizing can't move the plunger that is already moved into the closed position and hence no click. If the plunger remained down and was capable of carrying the necessary 150 amps give or take current, the starter would spin and wouldn't stop with the key OFF. If the starter is not spinning, check the voltage on the starter terminal of the solenoid to the engine block or battery -. ANY voltage there indicates welded contacts and a new solenoid. This welded contact condition could cause the case to heat up also.

Pitted but not welded high current contacts: Click should be audible, voltage present on output terminal to starter but starter doesn't roll......not enough surface area on solenoid contacts to supply necessary current to spin starter and voltage while starter is trying to spin would be well below 12v.....takes a min of 10v across the starter (input terminal to starter case) normally for a functional spin up...new solenoid.

Need more, ask.