I have one year-old Mallory YLM series distributors on my engines. Both start and run fine and both are wired identically. Since these distributors were installed, I have had recurring coil failures on the starboard engine after running long enough to get the engines up to operating temperature or perhaps a little longer. The port engine never fails but the starboard engine ignition breaks up so badly that the only way I can keep it going is to change the coil while underway.
This winter, I went through the ignition systems on both engines. Both use Mallory ballast resistors, caps, rotors, etc. all installed at the same time a year ago. The only difference I could find between the two engines' ignition systems was that the gap between the reductor (or whatever that 8-pont gear is called) and the magnet pickup on the port engine was a gap of close to .047" and that's what Mallory specifies. This is the way the distributor came, out of the box, and this is the engine that runs without a problem.
The starboard engine (the engine that keeps eating coils) showed a gap that was much wider an again, this is just the way the distributor came out of the box when new. To measure the gap, I used a little piece of Mylar film provided by Mallory. Beyond that, they have been no help.
I've adjusted the pickup on the offending engine to match the good port side engine. Now all I have to do is take a relatively long cruse to see if that difference in gaps was the problem.
If you know anything about Mallory YLM distributors, I'd love to hear your comments or suggestions.
Bill
This winter, I went through the ignition systems on both engines. Both use Mallory ballast resistors, caps, rotors, etc. all installed at the same time a year ago. The only difference I could find between the two engines' ignition systems was that the gap between the reductor (or whatever that 8-pont gear is called) and the magnet pickup on the port engine was a gap of close to .047" and that's what Mallory specifies. This is the way the distributor came, out of the box, and this is the engine that runs without a problem.
The starboard engine (the engine that keeps eating coils) showed a gap that was much wider an again, this is just the way the distributor came out of the box when new. To measure the gap, I used a little piece of Mylar film provided by Mallory. Beyond that, they have been no help.
I've adjusted the pickup on the offending engine to match the good port side engine. Now all I have to do is take a relatively long cruse to see if that difference in gaps was the problem.
If you know anything about Mallory YLM distributors, I'd love to hear your comments or suggestions.
Bill