Re: just got a sears elgin 7.5 need info
From the earlier recommended link:
The 1946 - 1954 Wico magnetos used three types of coils. The early coils are brown and have a 5/8" center lamination. These coils are usually still in good condition today and this type of magneto usually requires only a point cleaning and gapping to 0.020", and perhaps new spark plug wires. The second version magneto has the 5/8" laminations but the coils are covered with black plastic. These coils may be cracked but can be repaired with epoxy or other insulating material or they can be replaced with the earlier brown coils. The final magneto design uses black plastic covered coils with 7/16" center laminations. These coils are quite often cracked and may require replacement. If this type coil does need replacement, a 1950s style OMC coil can be substituted. On most models, the Wico points have a bakelite slider that slides in a groove in the magneto plate. This slider should be cleaned and lightly lubricated. Old oil or dirt in the groove can make the points sticky which results in a poorly running motor.
Over the years Sears recommended various Allstate, AC and Champion plugs for their motors. All of the 1946 - 1954 motors run well with modern Champion J11C plugs available at auto supply stores. The J11Cs come pre-gapped at 0.035"; this works fine for all the motors. The J11C is a little longer than the older spark plugs, and if your motor has a spark plug cover, care must be taken to make sure the spark does not jump to the cover.
