Info Please, I have a Lightwin 3 serial number 3018-09071 can anyone tell me the year, correct spark plug and fuel mixture. Also there is a tube that goes alongside the motor leading to the carb, does this require a sponge type air filter? Thanks in advance. Pappy
Your motor is a 1956 model, and it's 56 years old this year !!!!!
Use the Champion J6C sparkplug gapped to .025-.030". I believe those motors originally used a 16:1 fuel-oil ratio, 8 oz. ( 1/2 pint ) oil to 1 gallon of gas. With todays better outboard lubricants many folks run those motors at 24:1. That motor has brass bushings and not needle bearings so it needs a lot of lubrication to run well.
There is no foam air cleaner but may have had a perforated screen in front of the carburetor and held in place by the long tubular air silencer.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.