I am chasing a poor running condition on my 1989 Johnson 40HP, TJ40ELCEC. I have finally gotten it running enough to discover other issues. Yesterday, I discovered that it is firing the upper and lower spark plugs at the same time, but the lower plug does not fire when it is supposed to. How can this happen? PowerPack, charge coil, stator or ignition coil?
Here is how I have arrived at this observation. I searched this wonderful forum and am attempting to bring this engine back to life after it has sat for a couple of years. I rebuilt both carbs (with kits), replaced all fuel lines, cleaned and flushed the fuel tank and then gone through the link&sync procedure described in my OEM manual. I used a spark tester and both coils showed a sharp blue spark when set at 7/16". I could not get the timing correct using the method described here, but was able to get it "close". The engine will now run at a high idle, but the ignition advance for idle adjustment is at its max. While it was running, I decided to check the timing and found that the top cylinder was at approximately 4 degrees. I moved the timing light pick-up to the lower cylinder and found that it too was at the 4 degree mark. I removed the plug wire from the lower plug but there was no change in the engine; I could hear the spark jump as I was putting the wire back on, but still no change. I removed the upper plug wire and the engine immediately died. I checked the coils according to the manual procedure (basically resistance tests) and they were OK, but I don't know for sure. Compression on both cylinders is 105, cold and hot.
Any help on what to do next will be greatly appreciated.
Thanks,
Richard
Here is how I have arrived at this observation. I searched this wonderful forum and am attempting to bring this engine back to life after it has sat for a couple of years. I rebuilt both carbs (with kits), replaced all fuel lines, cleaned and flushed the fuel tank and then gone through the link&sync procedure described in my OEM manual. I used a spark tester and both coils showed a sharp blue spark when set at 7/16". I could not get the timing correct using the method described here, but was able to get it "close". The engine will now run at a high idle, but the ignition advance for idle adjustment is at its max. While it was running, I decided to check the timing and found that the top cylinder was at approximately 4 degrees. I moved the timing light pick-up to the lower cylinder and found that it too was at the 4 degree mark. I removed the plug wire from the lower plug but there was no change in the engine; I could hear the spark jump as I was putting the wire back on, but still no change. I removed the upper plug wire and the engine immediately died. I checked the coils according to the manual procedure (basically resistance tests) and they were OK, but I don't know for sure. Compression on both cylinders is 105, cold and hot.
Any help on what to do next will be greatly appreciated.
Thanks,
Richard