I have a newly acquired 1968 Johnson 1.5hp SC 10S. The previous owner stripped the spark plug threads, so I removed the head and installed a helicoil kit and a new J6 plug. The motor started with a couple pulls in a bucket so I took it to the lake where it delivered me halfway to my mooring and then died. It would not start and stay running for more than a few seconds. Today I bought a carb kit and rebuilt the carb. I didn't have any specs, so I set the float parallel with the top of the inverted bowl. I dismantled the carb completely, cleaned everything with carb cleaner and blew it out. The old packing washers were badly disintegrated. I have fresh gas at 50:1 and the tank is clean. There is a screen filter in the tank, but no inline filter. When I put it in the bucket, it started in a couple pulls, but did the same thing - ran for a minute or two then died. I suspected the coil at that point, so I put a spark plug test light inline with the plug, and waited an hour before trying again. It ran for it's usual minute and a half with good spark, but then died. It was still lighting the test light for as long as the flywheel was turning, so it doesn't seem like the coil is failing. (?) The fuel line is supplying gas to the carb, so I am stumped as to where to look next? I did pull the flywheel and cleaned and verified the points are at .020. The impeller looks newer, and is spitting water out while running, and I can keep my hand on the underside of the engine where the exhaust is, so I don't suspect overheating.
