72Glastron
Cadet
- Joined
- Jul 29, 2007
- Messages
- 14
I have 1972 Johnson 85hp with Points, CDI Powerpack (non tach wire), CDI coil V-4.
Recently this season, I ran into a major missfire situation that I was able to cure by cleaning the Distributor contact areas and the rotor contact area. Afterwards it ran great untill yesterday it starting acting up again. Thinking I had the same problem, I tore it down only to find the distributor and rotor are still very clean. I then started trouble shooting and found erratic off and on spark to #2 cylinder and weak spark to #4. I adjusted the points and even swapped them around with no change. If I disconnect all the spark plug wires I get great spark (1/2") from number 2. This is when I went to test the powerpack and coil. I swapped the coil with a known good one thinking it was coil failure, but same result. I then tested the blue wire from the Powerpack to coil and noticed black OOzing from my rectifier. the rectifier is cooked/burnt smell and outputing 18volts. I went ahead and tested my Powerpack and on my DMM only could get a max reading of 150volts during cranking. The powerpack has 12.4v going to it. That is 50 less then the desired spec. of 200 according to the flow chart.
My questions are:
(1) will the 150v from the powerpack cause the erractic no spark/weak spark or is it all in my distributor cap? I checked the #2 wire and found continuity, but what should it OHM out to?
(2) how can I properly test the stator output? I put my DMM on the two yellow wires outputing from the stator and the AC voltage was everywhere on the meter for me to get a reading.
(3) If it is in the distributor cap, where can I find one? I have looked at parts online and cant seem to come up with one.
Sorry for the long thread, but I am at a loss for which componant is failed.
Sam
Recently this season, I ran into a major missfire situation that I was able to cure by cleaning the Distributor contact areas and the rotor contact area. Afterwards it ran great untill yesterday it starting acting up again. Thinking I had the same problem, I tore it down only to find the distributor and rotor are still very clean. I then started trouble shooting and found erratic off and on spark to #2 cylinder and weak spark to #4. I adjusted the points and even swapped them around with no change. If I disconnect all the spark plug wires I get great spark (1/2") from number 2. This is when I went to test the powerpack and coil. I swapped the coil with a known good one thinking it was coil failure, but same result. I then tested the blue wire from the Powerpack to coil and noticed black OOzing from my rectifier. the rectifier is cooked/burnt smell and outputing 18volts. I went ahead and tested my Powerpack and on my DMM only could get a max reading of 150volts during cranking. The powerpack has 12.4v going to it. That is 50 less then the desired spec. of 200 according to the flow chart.
My questions are:
(1) will the 150v from the powerpack cause the erractic no spark/weak spark or is it all in my distributor cap? I checked the #2 wire and found continuity, but what should it OHM out to?
(2) how can I properly test the stator output? I put my DMM on the two yellow wires outputing from the stator and the AC voltage was everywhere on the meter for me to get a reading.
(3) If it is in the distributor cap, where can I find one? I have looked at parts online and cant seem to come up with one.
Sorry for the long thread, but I am at a loss for which componant is failed.
Sam
