This little 3.9 hasn't been run in probably 25 years. I did some maintenance on it and tried to bring it back to life. My surprise it popped off about the second pull but didn't run more than 10 seconds and died. I should have replaced the gas line tank/motor that I think created the black sediment I found in the carb. I cleaned everything up again, replaced the line and tried again but it would not start. I did install a new plug, parts list called for a center fire plug it had an J electrode plug. I don't remember if the plug looked bad enough to be considered fouled or not and now it's mixed with all the other old plugs so I can't tell which it was or even if it was the right J style for the motor. Anyway after replacing it fire right up but only ran maybe 10 seconds and died again. Eventually found the new plug fouled. Checked the spark and could get it to jump 1/4" by spinning the flywheel by hand. Again remixed new gas to make sure it had the correct oil mix. It kept starting right away but would die after running less than a minute with the plug fouled. Started to lean it out but eventually got to the point where it would not start. Always the same, plug fouled after 10-20 seconds. Cleaned the plug and it fired right back up.
All the literature and the previous owner say the fuel mix 50:1 but it is making me wonder if there were any exceptions? I know I had an older Merc, 150 that I thought was 100:1. What else should I be checking?
All the literature and the previous owner say the fuel mix 50:1 but it is making me wonder if there were any exceptions? I know I had an older Merc, 150 that I thought was 100:1. What else should I be checking?
