On another thread I recently posted I described a sudden engine shutdown problem. I was able to trace the cause to the coil and after replacing it with a MM coil the trusty A4 came back to life. However, that still left me with the nagging doubts as to the root cause of my coil problem. Here is what I posted on the other thread -
I should say that my alternator is also the original Motorola 35A. Anther forum member suggested that hot coil maybe due to high alternator output which is confirmed by my voltage testing - it shows 18-20V. So, I have spent all morning reading on possible cause and cure for high voltage output. On another thread Shawn suggested that high alternator output could be caused by bad regulators and recommended a source for a bolt on replacement. However, I when I clicked on the ASE Supply Outlet Store link I was not able to find the replacement regulator. Does anyone know another source for a direct replacement regulator for the original Motorola alternator?
Thanks!
Ray Chang
Triton106 - Alameda, California
Ok, here is the follow up. Today, armed with new coil, points, condensers, distributor cap I was ready to tackle the no spark issue.
First thing I did is to replace the coil with the backup coil I bought from Moyer Marine a couple of years ago (maybe even more than a couple). The reason I suspected that coil was the cause is because I already checked voltage on the coil primary circuit and got 12V last week. In addition, when I cranked the starter I can see the voltage drop to 8/10V.
In any case, I moved the location of the coil from the back of the engine block to the engine room bulkhead to get better access. I hooked up the wirings and turned on the starter. On the first try my trusty A4 fired right up. Great, right?
No, after running it for 15 minutes or so the coil got hot (I can still hold it, though, without having to pull my hand back). Is that normal? The old (bad) coil is oil filled (I can hear it when I shake it) and the new Moyer coil is probably epoxy filled. I understand oil filled coils run cool. Should I expect the epoxy filled coils to run a littler hotter? [Edit - correction, according to MM their coils are oil filled and actually oil filled coils are hotter because they dissipate heat better.]
What troubles me more is that I still don't know what cause the coil to break. I tested for shorts between the secondary terminal and the case and found none. The original coil has been in the boat since I bought it in 2000. Could it be age? What is the expected life of a coil? Could it be due to the electronic ignition that I installed a couple of years ago? Hmmm....
First thing I did is to replace the coil with the backup coil I bought from Moyer Marine a couple of years ago (maybe even more than a couple). The reason I suspected that coil was the cause is because I already checked voltage on the coil primary circuit and got 12V last week. In addition, when I cranked the starter I can see the voltage drop to 8/10V.
In any case, I moved the location of the coil from the back of the engine block to the engine room bulkhead to get better access. I hooked up the wirings and turned on the starter. On the first try my trusty A4 fired right up. Great, right?
No, after running it for 15 minutes or so the coil got hot (I can still hold it, though, without having to pull my hand back). Is that normal? The old (bad) coil is oil filled (I can hear it when I shake it) and the new Moyer coil is probably epoxy filled. I understand oil filled coils run cool. Should I expect the epoxy filled coils to run a littler hotter? [Edit - correction, according to MM their coils are oil filled and actually oil filled coils are hotter because they dissipate heat better.]
What troubles me more is that I still don't know what cause the coil to break. I tested for shorts between the secondary terminal and the case and found none. The original coil has been in the boat since I bought it in 2000. Could it be age? What is the expected life of a coil? Could it be due to the electronic ignition that I installed a couple of years ago? Hmmm....
Thanks!
Ray Chang
Triton106 - Alameda, California
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