Sunshine 5 HP two stroke engine

made by H.V.McKay in Sunshine, Victoria, Australia in 1922/23


This engine is a simple two stroke engine.  It is lubricated by three drip oilers and a rate of six drops per minute for each oiler.  There is no need for premix fuel or oil injection as in the case of modern two strokes.  The engine here is as we purchased it for our collection.  When we stripped it down it was found to be in good shape.  A few minor things needed attention of course, like the gauze in the intake manifold, but it was largely good to go.  After building a transport and cooling tank for it we reassembled it and away it went.  We decided to not even repaint it and are happy to watch it tick over at 350 rpm. Perhaps of interest is the oiler setup, because a two stroke engine has a pressurized crankcase the oilers need to seal against blow-back.  These oilers do not have a ball bearing as a valve, they infact have a 'T' shaped round valve that fits into them and a machine threaded screw that holds the little valve in place.  The machine threaded screw is hollow, it has a one eighth hole in it two thirds of the way through, then it has a one sixteenth hole through the rest of the way.  In both the top and bottom of the screw is a flat screw-driver slot one at ninety degrees from the other.  With the fuel tank at the bottom of the engine the pressure in the crankcase is put to good use in operating the fuel pump, which is a simple diaphram pump.