Well, my first thread got closed before the issue was wrapped up, so I'll pick up from here.
In the first thread, I was having problems where the engine would die after 15 minutes of full throttle operation, or slightly longer at less than full throttle. Not a fuel issue, but something electrical. I found I could pour some water over the CDI module and get the engine started right away, or I could wait 10-15 minutes and it would run again. I would first notice the engine start to stumble at high throttle settings, then as I slowed down the engine would continue to stumble. If you got down to idle it would die and you could not restart it.
After weeks of repeating the failure mode and recovery, I was convinced the CDI module had a heat-related failure. The other thing I had noticed with it -but much before any failure symptoms- was that it was on a fixed 25 degree advance. The specs call for it to be about 5 degrees at idle and increase to 25 at around 3000 RPM (don't remember the exact spec). It had run fine for several years. One day, after putting on a tach (the kind that wraps around the plug wire), I started to get the "heat related" failures.
So I bought a new CDI thinking that was the culprit. Well, I think I was wrong. I still have a similar failure now, but the symptoms are slightly different. Now I don't notice anything when I'm at full speed, but when I drop down to lower RPMs (less that 2000 or so), it becomes intermittant. A quick blip of the throttle MAY save it from stalling, but if it stalls you can't restart until you "cool the CDI'. I put that in quotes because now I don't know if I'm actually doing something by "cooling the CDI" or if it's just the time elapsing. I haven't done it enough or just waited a couple minutes to see if would would restart without "cooling the CDI". Haven't had to long enough on the water to experiment. Trying to figure out how to duplicate the failure mode in a tank so I can troubleshoot at home.
In the first thread, I was having problems where the engine would die after 15 minutes of full throttle operation, or slightly longer at less than full throttle. Not a fuel issue, but something electrical. I found I could pour some water over the CDI module and get the engine started right away, or I could wait 10-15 minutes and it would run again. I would first notice the engine start to stumble at high throttle settings, then as I slowed down the engine would continue to stumble. If you got down to idle it would die and you could not restart it.
After weeks of repeating the failure mode and recovery, I was convinced the CDI module had a heat-related failure. The other thing I had noticed with it -but much before any failure symptoms- was that it was on a fixed 25 degree advance. The specs call for it to be about 5 degrees at idle and increase to 25 at around 3000 RPM (don't remember the exact spec). It had run fine for several years. One day, after putting on a tach (the kind that wraps around the plug wire), I started to get the "heat related" failures.
So I bought a new CDI thinking that was the culprit. Well, I think I was wrong. I still have a similar failure now, but the symptoms are slightly different. Now I don't notice anything when I'm at full speed, but when I drop down to lower RPMs (less that 2000 or so), it becomes intermittant. A quick blip of the throttle MAY save it from stalling, but if it stalls you can't restart until you "cool the CDI'. I put that in quotes because now I don't know if I'm actually doing something by "cooling the CDI" or if it's just the time elapsing. I haven't done it enough or just waited a couple minutes to see if would would restart without "cooling the CDI". Haven't had to long enough on the water to experiment. Trying to figure out how to duplicate the failure mode in a tank so I can troubleshoot at home.