Classic Mini bike Engines

Making a Tecumseh Snowblower Engine Look Vintage

As a kid, the Honda bikes were what we dreamed of owning.  Their motorcycle feel with steering head bearings and a transmission were high end features in a day when lawnmower type flathead engine powered mini bikes were the norm.  I remember as a kid, looking for the reel type lawnmowers that had horizontal shaft engines.  Hoping to find one no longer being used and pulling the engine off to put on a mini bike I didn’t even have at that point!  They were around in the late 60s, early 70s, but were usually 2 or 2.5 hp maximum.  My first “go kart” was one my Dad built, using parts from an old baby carriage and a sheet of plywood.  I pestered Dad until he finally conceded to find an engine to bolt onto the back of it.  I believe it was 1967 or 1968 in Ancaster when we found an old outdoor wringer washing machine engine.  Yes, gasoline powered washing machines were common up to the 1960s.  They were only 1.5 hp and had no recoil start, just the hub you wrapped a rope around to start.  Without a clutch, just a belt to a pulley bolted onto the rear wheel, it would sort of keep the kart going if you pushed it on a flat road first.

Hay elevators used small 4 stroke B&S engines and I became aware of this around 1969 or 1970.  Two uncles that farmed would accept any help available to bring the hay in.  For me, this was awesome!  I got to start the elevator engine, (a thrill in itself) and ride on or drive the tractor.  Farming was so mechanical by then, I just loved being around all that machinery.  I’m sure Mike remembers and may even still have the elevator engine, used years ago at the family farm.

But I digress.  This is about the two main power sources for the wonderful vintage mini bikes we love.  Briggs & Stratton and Tecumseh.  The bikes I remember with B&S engines were either old ones from the 60s or someone had swapped it on there, themselves.  I say this because B&S stopped supplying mini bike manufacturers with engines in 1969.  Almost every other bike made after that, using a 4 cycle engine, used a Tecumseh engine.  The common horsepower on these bikes was either 4 or 5hp.  Some were direct chain drive, through a centrifugal clutch to a sprocket on the rear wheel.  Others used a jackshaft, allowing further gear reduction without a massive rear sprocket being too close to the ground.  The top of the line bikes used a torque converter, a simple version as used on all snowmobiles.  This gave great hill climbing ability and top speed.  John V’s DMP uses a torque converter.  Although very hard to find an original old Tecumseh or B&S motor, there is hope; especially in Canada.  Many snowblowers used 5 hp Tecumseh engines and they’re laying around, even being given away.  These can be easily retrofitted to look vintage.  An added plus is all the ones made in the 90s had CDI ignition, making starting a breeze and spark plug changing a thing of the past.