lighting coil
- Thread starter Rick Adams
- Start date
- Tags coil lighting
gave you that answer on another thread, What years are you engines? the flywheels have to match the shroud.....HS50 never came from the factory with the curved top shroud they used a heavier/thicker wheel which Tecumseh did not start to use on the HS40 till 1974 so early 1970's they do not fit...at least correctly.
Two items determine whether the flywheel will work. One, as said above is the type of shroud. The newer more square'ish shroud will fit the older style flywheel, but not visa-versa.
Second and more important is the taper of the crankshaft end the flywheel fits on. The HS series engines had two tapers, dependent on what application the engine was originally designated for. Easiest way to determine which taper you have is by the size of the threads on the end. 7/16" x 20 or 1/2" x 20. The Rupp's style HS40 engines and the HS50 engine used on my '72 Speedway Greenhorn used the 7/16" x 20. But I have a points style HS50 from a Craftsman snow blower that has the 1/2" x 20 threads. The bad part (trust me) when buying a flywheel, the seller is usually clueless on which taper he has.
Second and more important is the taper of the crankshaft end the flywheel fits on. The HS series engines had two tapers, dependent on what application the engine was originally designated for. Easiest way to determine which taper you have is by the size of the threads on the end. 7/16" x 20 or 1/2" x 20. The Rupp's style HS40 engines and the HS50 engine used on my '72 Speedway Greenhorn used the 7/16" x 20. But I have a points style HS50 from a Craftsman snow blower that has the 1/2" x 20 threads. The bad part (trust me) when buying a flywheel, the seller is usually clueless on which taper he has.