generator12
Senior Chief Petty Officer
- Joined
- Jul 9, 2010
- Messages
- 666
In 2010 I reported in this forum about a "Pertronix failure" on my 1986 Merc. 170. I had been on the water, engine shut down, no spark, and I got home after I replaced the Pertronix with the original breaker points. Happened twice, so I sent the Pertronix back to RetroRockets and Carl Dudash sent me another.
In 2011, after another similar sequence of failure on the water, I had no spark with the Pertronix but the breaker points worked. During my subsequent testing on the muffs, I found that leaving the tach wire off the coil appeared to make the engine more stable with the Pertronix operating, so I left it off for the whole season and ran with the Pertronix. The engine ran much more smoothly with this than it had with the points, as long as the tach wire was off.
I checked this wire with a digital multimeter (tach end disconnected) and found infinite resistance to battery negative ("ground"). With the engine running, there were no stray voltages or apparent cross-talk with other systems. Therefore I assumed the problem was tach failure occurring after an hour or so of running, and my intent was to replace it.
A few days ago I started her up in the driveway and the failure occurred within about five minutes. (Finally! I could now troubleshoot it at home!) Only this time it was not erratic - it was a hard failure. Just touching the tach wire to coil negative would bog her down immediately. Disconnected the other end of the wire from the tach itself, and the problem remained. It was the wire itself.
The strange thing is that I couldn't find anything wrong with this wire with my meter. No high-resistance ground, no voltage leakage from another source - NOTHING...! The only way to check the wire was to use engine operation as my measurement.
So I replaced it with a piece of stranded THHN and all is well. Two points here:
1. Electronic ignition systems are higher impedance than breaker points, and therefore more vulnerable to stray voltages and/or resistance problems. Something occurred with it that the more robust breaker points could overcome.
2. Dudash and RetroRockets stick with the customer. He worked with me every step of the way through email and phone conversations to make things right.
I had a good experience with the guys on this board on this topic, so I wanted to share the information.
In 2011, after another similar sequence of failure on the water, I had no spark with the Pertronix but the breaker points worked. During my subsequent testing on the muffs, I found that leaving the tach wire off the coil appeared to make the engine more stable with the Pertronix operating, so I left it off for the whole season and ran with the Pertronix. The engine ran much more smoothly with this than it had with the points, as long as the tach wire was off.
I checked this wire with a digital multimeter (tach end disconnected) and found infinite resistance to battery negative ("ground"). With the engine running, there were no stray voltages or apparent cross-talk with other systems. Therefore I assumed the problem was tach failure occurring after an hour or so of running, and my intent was to replace it.
A few days ago I started her up in the driveway and the failure occurred within about five minutes. (Finally! I could now troubleshoot it at home!) Only this time it was not erratic - it was a hard failure. Just touching the tach wire to coil negative would bog her down immediately. Disconnected the other end of the wire from the tach itself, and the problem remained. It was the wire itself.
The strange thing is that I couldn't find anything wrong with this wire with my meter. No high-resistance ground, no voltage leakage from another source - NOTHING...! The only way to check the wire was to use engine operation as my measurement.
So I replaced it with a piece of stranded THHN and all is well. Two points here:
1. Electronic ignition systems are higher impedance than breaker points, and therefore more vulnerable to stray voltages and/or resistance problems. Something occurred with it that the more robust breaker points could overcome.
2. Dudash and RetroRockets stick with the customer. He worked with me every step of the way through email and phone conversations to make things right.
I had a good experience with the guys on this board on this topic, so I wanted to share the information.
