I've been trying to trouble shoot some electrical problem on my '69 Z-50 for awhile now, and I think I've narrowed it down to the coil. I'm a little skeptical thats the problem, as I've read they don't go bad very often. I should also mention that I installed a new condenser about two years ago, and it ran strong (first kick start everytime) up until about six months ago.
The main problem is the bike has intermittent spark. After sitting, sometimes it does and sometimes it doesn't. When it starts, it'll randomly die while riding it, then won't start again (then I check the spark, and it's gone).
At first I thought it was a bad ground on the ignition switch, so I started by unplugging the ignition switch to bring that out of the equation (as it should still run without it), and it has the same intermittent spark problems as before.
Then I decided to check the resistance in the main coil (the one under the gas tank), and it would jump between reading open and around 20,000 ohms. Is this normal? Is there a factory spec that this reading should be? I've searched the web and this forum and haven't found one. Also, the spark plug wire coming out of the coil feels very loose, is this normal? While measuring the resistance as I moved that wire around the resistance would jump to open, then settle back down to the around 20,000 ohms. But when the bike randomly decides to run, moving that connection does not kill it.
Next I'd like to pull the flywheel and check the coils in there, but once again I'm curious as to what resistance they should be at. Also, if those look good, I'm going to pull all the factory tape off the harness and double check the wireing.
Anything else I'm missing? And thanks in advance, and sorry if this question is a little wordy.
The main problem is the bike has intermittent spark. After sitting, sometimes it does and sometimes it doesn't. When it starts, it'll randomly die while riding it, then won't start again (then I check the spark, and it's gone).
At first I thought it was a bad ground on the ignition switch, so I started by unplugging the ignition switch to bring that out of the equation (as it should still run without it), and it has the same intermittent spark problems as before.
Then I decided to check the resistance in the main coil (the one under the gas tank), and it would jump between reading open and around 20,000 ohms. Is this normal? Is there a factory spec that this reading should be? I've searched the web and this forum and haven't found one. Also, the spark plug wire coming out of the coil feels very loose, is this normal? While measuring the resistance as I moved that wire around the resistance would jump to open, then settle back down to the around 20,000 ohms. But when the bike randomly decides to run, moving that connection does not kill it.
Next I'd like to pull the flywheel and check the coils in there, but once again I'm curious as to what resistance they should be at. Also, if those look good, I'm going to pull all the factory tape off the harness and double check the wireing.
Anything else I'm missing? And thanks in advance, and sorry if this question is a little wordy.