Have turned the switch to the off position yes.

I stepped out of this for a bit... in an earlier post you said you have basically just been using a long handled insulated screw driver to jump the current from the solenoid directly to the starter.
I am most likely misunderstanding but if you have current at the solenoid but not at the starter than it seems that the solenoid would be a logical place to investigate?

^That is what I would guess too.

Possible free repair, take starter off engine. Remove solenoid and inspect for scratches on plunger and heat damage.(leaking wax from windings inside) Polish plunger or sand it down a few thousands of an inch. Carefully reassemble and bench check before installing on engine.This was the final fix on mine.

That is most likely the case_the challenge of course is that the solenoid seems to function perfectly when cold_.just not when hot_I was wondering if there were any other potential ideas for this scenario_.I do think the battery cable suggestion has potential so I will explore that first and then move on to the solenoid as there are a few good suggestions on what to try there as well. Thx again for all of the help everyone !!!!

For what it's worth, I just replaced the starter button on the engine control panel today. Over the past month you really had to mash the button down to make it work, then it finally failed this weekend. I actually started the engine using the hand crank with the compression reliefs open. The new switch cost $30 with tax, and works like a charm. It gave me another idea for troubleshooting your problem.

There is a connector at the aft end port side of the 2GM that joins the harness to the engine control panel. If you unplug this, the two fat lugs are for the starter switch, and all the others are for the sensors & idiot lights. Try unplugging the connector, and on the engine side take a pair of needle nose pliers to jump the two fat lugs. This should engage the starter, through the starting solenoid. If it works, then maybe you have a bad contact somewhere upstream to the push button on the engine control panel.

Sorry if this has been mentioned.

Resitance in bad connections tends to increase dramatically with higher temperature. Might be in the solenoid or the connections to it.

Thanks Bill and Mark for the suggestions/ideas_.I have the QM15 however it has the same connectors that you referenced Bill only located at the port aft rear of the engine. I will try out your suggestion, not to mention those connectors are likely due for replacement as are my battery cables.

Our season only has a few months left so I will likely do the rest of this in the off season including taking on the solenoid. I have noticed that every small connection I replace seems to improve things a bit so I think it is a cumulative effect of many old and worn out cables/connections. Can hardly fault them as the boat is over 30 years old__

Had the problem yesterday while out fishing. Shut off engine to jig by a bouy for ten minutes. Heat soak stuck solenoid. Slight draw[slight dimming of panel lights when pushing starter button]. Jumped from battery cable to solenoid activation connection. That unstuck the solenoid which then worked from the starter button. The overheat beeper and light stayed on for a good two minutes until the hot spots in the block equalized.{heat soak} No further problems and the starter was fine when rechecked at the mooring. This problem has come up in the past, after a long run and sitting off for several minutes. Same as yesterday, not a problem when you turn it off and restart shortly.

Bob - I hate to say it, but sounds like you have the same problem I had on Rhapsody with clogged cooling passages. Is your engine raw water cooled? If so, check out the description of the symptoms on my 2GM rebuild.

I now make sure that before the engine is shut down that it is run at about 1200 rpm with no load for 5 minutes to cool down the block and prevent salts & scale from depositing in the cooling passages due to boiling water.