Old post but this pertains to the subject…. Customer dropped this engine off to be rebuilt, it is the prototype/example engine that Tecumseh setup for Roper/craftsman/sears for the 4hp version of these bikes.
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The owners grandfather was associated with Sears Corprate, I think he said advertising/marketing . Somehow he got the first 2 bikes off the assembly line for his grandkids.
these particular engines were pretty unique, since they used a battery to comply with certain laws for street use, they had a charging system which is different than a lighting system setup. Not something commonly used on the small frames at the time because those were really only used for electric start. All the lights horn etc ran off the battery and the engine charged the battery. This was also at the transition point for Tecumseh to offer Taylor spark arrestor headers for the first time other little changes.
While the 3amp DC charging system is rare to see (researching found only 4 model numbers of the HS40 got them in the books) this one is in fact the “EXE” numbered tag to back up its history. These tags were put on engines that were not intended to be out on the market they were for manufacturers to use to setup the machine they were making or use as examples etc..
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I went down to the archives
and did a deep search to do some cross referencing and was able to find thanks to a list of craftsman mini bike specific built engines I have that this would become a 143.617092, which in Tecumseh numbers was a 55333C
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so with all that and and his grandfathers connection to sears….I would not doubt that the bikes you see in the original adds are the ones they got as kids!!!!!
reposting the photo from above but this IS thanks to
@Smallbore for finding/buying catalogs till he found the match to the bike he bought many years ago
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