Boatsnhoes
Contributing Member
Hi all,
New member here. I bought a 1959 Mercury Mark 35a in non-working condition. I've been running through the systems one by one and thought I had everything in place. Pulled the starter and got nothing.
I suspect it may be due to weak spark since the magneto is so old.
I tested the magneto without a battery attached before trying to start - all the plugs get a blue spark without issue just from spinning the magneto by hand. Order is correct. I just don't think it's a strong enough spark because I can't think of what else it is (compression is good carbs are clean yada yada).
The magneto generates an electric field (supposed to be 12V) which is used to feed the ignition coil, but it also seems to have a terminal where a positive wire can be connected as part of that same circuit. This is where the question comes in: can I just connect a 12V battery to that lead and bypass the magnetic generator part of this entirely? That way I can be sure the coil is getting 12 strong volts when the points (aka breakers) open up, and my spark is as strong as can be.
The terminal in question is shown in this video (click link and it'll bring you to the right time, 1:58 or so) https://youtu.be/d_il7Q7N14o?t=112
It's the terminal where the white haired guy attaches the red lead. They also make some sort of a comment about a switch that I don't understand. I guess what I'm asking is what is supposed to be there? A positive lead from the battery? They mention a switch of some sort?
I looked around and didn't see any examples of others wiring a battery directly, but it seems like it should work.
If anyone else has tips any other tips at all on getting this kind of motor going I'm all ears.
Thanks! Glad to have finally joined. Thanks to Dangar Marine on YouTube for the recommendation.
New member here. I bought a 1959 Mercury Mark 35a in non-working condition. I've been running through the systems one by one and thought I had everything in place. Pulled the starter and got nothing.
I suspect it may be due to weak spark since the magneto is so old.
I tested the magneto without a battery attached before trying to start - all the plugs get a blue spark without issue just from spinning the magneto by hand. Order is correct. I just don't think it's a strong enough spark because I can't think of what else it is (compression is good carbs are clean yada yada).
The magneto generates an electric field (supposed to be 12V) which is used to feed the ignition coil, but it also seems to have a terminal where a positive wire can be connected as part of that same circuit. This is where the question comes in: can I just connect a 12V battery to that lead and bypass the magnetic generator part of this entirely? That way I can be sure the coil is getting 12 strong volts when the points (aka breakers) open up, and my spark is as strong as can be.
The terminal in question is shown in this video (click link and it'll bring you to the right time, 1:58 or so) https://youtu.be/d_il7Q7N14o?t=112
It's the terminal where the white haired guy attaches the red lead. They also make some sort of a comment about a switch that I don't understand. I guess what I'm asking is what is supposed to be there? A positive lead from the battery? They mention a switch of some sort?
I looked around and didn't see any examples of others wiring a battery directly, but it seems like it should work.
If anyone else has tips any other tips at all on getting this kind of motor going I'm all ears.
Thanks! Glad to have finally joined. Thanks to Dangar Marine on YouTube for the recommendation.