I have got a Hatz Diesel
in a G&M Marine Generator
which was bought on an online auction
site. It was an extremely bad buy as the oil turned out to be so loaded with iron that it was highly magnetic.
The engine is based on an obsolete Hatz cement mixer engine that has had water cooling
added. The water cooled Hatz is an HE673. The lack of an oil pump and filter means that the engine oil should be changed very frequently, say every 50 to 100 hours of running. Sucking the oil out with a pump from the filler hole is NOT GOOD ENOUGH as the drain plug
needs to be removed and its magnet needs to be cleaned every time. In effect the sump plug
the oil filter
My engine is seized solid and I think that the connecting rod is friction welded to the crank-pin. So much for "Won't start or run". In British English
an engine which "won't start" is deemed to be one that turns around when cranked by the starter but won't produce any power. "Seized-solid" is something completely different.
On these engines the crank-case is light alloy which does help to keep the weight down. As to the Hatz flywheel generator
, this is present on the G&M but is not connected. Nowadays there are other ways of regulating charge current
which are superior to shorting-out tertiary coils with Triacs. Something along the lines of a "Simple Switcher" (tm) might be a better bet. For those who still use the flywheel alternator it might be a good idea to fit Zobel Networks and/or Voltage Dependent Resistors to the parts where the voltage spikes are produced.
Sadly George Huxtable who knew a lot about these engines passed away in December 2011. His own engine worked for over twenty years although he did adapt it to use a car alternator after two stator failures.
For parts it is advisable to try an industrial engine specialist first rather than a chandler. Bolts, screws and ball races will be to ISO standards and the sea-water pump is by Johnson so get as much as you can at generic prices.
Performance wise, allegedly these engines do not really have sufficient power to "punch" a 4 knot
tide in a 27 foot long keel-boat. At this power level barnacles
, excess weight and a coked-up engine can really slow things down. It is an AUXILIARY engine not intended for water-skiing! At these power levels and boat lengths hull speed
will only be about 5 knots so running against a 4 knot
ebb-tide will result in a speed of only about one knot over the ground. Thrifty sailors will save their fuel
until the currents are more favourable but these days some people will demand 30 HP or more in order to go whenever they want.