Need help with old Merc ignition !!!!!!!!!!

[nortface]

Desperately needing all the expert advice possible. My 1967 Mercury 1100 (s/n: 2114850) was in the shop to get it running for our maiden voyage this Sunday. The mechanic hot wired the motor overriding the remote controls. Motor started right up and ran very strong. As soon as he'd let his thumb off of the starter button the motor would die. Tried numerous configurations with jumper leads to try and isolate the problem. Called the Mercury factory for help to no avail. Put a meter on the various ignition components and everything checked out okay. My mechanic is stumped, but believes there is an errant ground path that is just not obvious. Suggested systematic changeout of components with no guarantee that it might be the fix (i.e. switch box assembly, distributor, etc.)<br /><br />Has anybody ran into this problem before, and be able to offer a solution without me having to spend $300-$400 a whack without knowing if it will correct the problem. <br /><br />I'll name my next child after the person that can help!<br />George

 

[mnmfors]

Re: Need help with old Merc ignition !!!!!!!!!!

I am probably not an expert you were looking for, but I have a few old inline 6 mercs.<br /><br />If you have the wrong switch, it may be automotive and not marine. May cause this condition I think (someone correct me if I am wrong)<br /><br />Mercury made various different ignition systems, and unless it is type three, you need special equipment to test distributor or switchbox. (which seem to be the common problems) Your mechanic should have this equipment. A multimeter will not cut it according to my manual. I would definately consult a different mechanic if he cant isolate the problem, or at least elimanate most parts as suspects. Heck, you could just guess and replace parts at random yourself, right?<br /><br />In my manual, it just suggests to take the components off and bring to a dealer.<br /><br />I just got my manual today and it was really a good investment. (if you dont already have one)<br /><br />Sorry I couldnt be more help. Someone may be along shortly with better answers.

 

[flatsman]

Re: Need help with old Merc ignition !!!!!!!!!!

Search thru the previous post as these old engines are still in service. Check simple things first --how about ignition switch ?

 

[nortface]

Re: Need help with old Merc ignition !!!!!!!!!!

I truly appreciate the suggestions. The motor was hot wired through the starter and coil. At one point the mechanic disconnected the harness and the same problem occurred. I would think that the ignition switch would be out of the equation. I believe the 1967 is a Type II system. I've got a Seloc manual with the same instructions....take it to a dealer. <br /><br />I'm planning to take a very close look at the distributor cap tomorrow to see if there are any hairline cracks. Do you think the problem could be that simple???<br /><br />George

 

[mnmfors]

Re: Need help with old Merc ignition !!!!!!!!!!

Sounds like what could be happening is that the switchbox is only getting power when cranking. And that power is from the stator/rectifier? <br /><br />I am pretty sure that there should be a jumper from white to red. <br /><br /> DC Volts to the red (charging) coming from the rectifier. 12v supply coming from the battery. In your case, 12v is fed into your switch, then back to your switchbox. This would be the white wire. Check to be sure it has 12v with key on. If not I bet this is your problem. <br /><br />Other things to try...<br /><br />Of course, check all grounds and clean all terminals, inspect wires, etc.<br /><br />Make sure your harness plug is free of corrosion.<br /><br />Disconnect kill wire. Check yourself but I think it is brown right under the coil wire<br /><br />I believe we have the same manual, I am getting your wire colors from page A-25. Please double check.<br /><br />Good luck I hope this helps.

 

[12Footer]

Re: Need help with old Merc ignition !!!!!!!!!!

Not 100% sure, but I believe this model had no switchboxes, but rather, had a magneto ignition?<br />If so, there is a salmon colored wire on the side of the distributor/magneto. disconnect it, and the one going from it to the mercury switch, and see how it runs. <br />If it runs, your mechanic is correct in assuming a ground path.<br /><br />disconnect the battery, and place your meter on ohms scale.<br /><br />Attach one lead to the engine frame, and the other to the salmon wire. If shorted, you must back-trace it to find the culprit,(the meter will indicate an "open" condition when you find the short). <br />Outside of the harness itself, there is a "mercury switch" that also grounds-out the mag,in the event of an unlevel engine, and it may be shorted, or the engine not level. So can ignition switch be shorted to ground in the "run" position.<br /><br />.

 

[dave68]

Re: Need help with old Merc ignition !!!!!!!!!!

had a problem some what the same mine ended up being a bad wiring harness conectionright at the motor

 

[nortface]

Re: Need help with old Merc ignition !!!!!!!!!!

Verified all wiring is per schematic. Checked voltage and resistence, again everything okay. Problem still exists! My internal harness is pretty bad, I've taped things up for the time being to make sure no copper is exposed. <br /><br />George