The Power Mountain Bike

Photo of the Power Mountain Bike.
Photo of the engine.
  This bike resulted after we received a 2.5 hp Honda 4-cycle engine, a
real gem. It weighs 19 lbs. and runs all day at 3500 RPM. The centrifugal
clutch engages at 2250 RPM. The belt ratio is 3" to 5", the chain ratio
is 13T to 44T, so the overall reduction is 5.64:1. At 3500 RPM, the speed
is up to 45 MPH. The 44T sprocket was initially clamped to the left side of
the rear wheel hub with a U-bolt clamp aided by industrial epoxy.  This had
to be changed to being welded to the hub.
  The engine mount is welded to the bottom bracket.  The pedals had to be
extended to avoid hitting the engine as you pedal.  Leaning into the turns too
much while pedalling can cause the pedals to scrape on the road.
  The throttle lever is on the left handlebar, above the brake lever and
closer in. There is just enough room under the top tube to remove the gas cap
and fill up. The choke, fuel valve and starter pull handle are easily reached
by the seated rider. The ignition kill switch is in front of the engine.
  Single-pull starts are common. The muffler is very quiet.  The photos
show the bike without the belt guard in place.