Fuller & Johnson built a second, much larger pumping engine known as the Big 4 Pumper that was intended for heavy duty and deep well pumping.  It certainly has to be the most unusual engine to ever come out of the Fuller & Johnson factory.  The basic design was a vertical water cooled headless engine with ported exhaust.  A friction hand clutch allowed the engine to be started without a load.  A low tension ignition system was devised using a Bosch 32 oscillating magneto.  It was tripped by an extension on the pivoting exhaust lever.  A rod attached to a special trip casting on the mag went up to hammer the ignitor points open.  An interesting coincidence is that none of the surviving Big 4 Pumpers has an intact ignition system!  Some parts like the muffler, fuel pump, piston/rod and crankshaft were borrowed from the Double Efficiency.  Others like the governor weight and detent lever were modified from the DE design.  It has also been noted that a change in the governor weight and flywheel was made, probably late in production.  It's likely production of the Big 4 started after that of the Double Efficiency and Farm Pump Engine around 1911 and the production run was limited to about 100 units.  The Big 4 was not aggressively advertised by F&J, only two ads have surfaced showing them.  A reference is made to a factory catalog but nothing has come to light yet.  To date only a sole example of this magnificent pumping engine is known to be in the US.  However, at least 11 are known to exist in Australia in one form of completeness or another.  The majority of those being around or having come from Toowoomba Queensland.  Toowoomba was home to Southern Cross who copied the Farm Pump Engine, and it is known they also built at least two copies of the Big 4 Pumping engine.

The Big 4 was a self contained pumping giant!

The oscillating mag, ported exhaust and pumping gear can be seen in this engraving.