Most of Mazda engine aircraft crashes are due to bad
plumbing; fuel, water and exhaust.

IIRC, the only one which was actually an internal problem was one guy
who built up his engine without an oil pump, and didn't put enough oil
in his fuel mix.

Keith


I am familiar with that report. I think it was a Coot that
spun in and burned. Engine quit, guy turned back and stalled
due to aft CG. Ken Welter knew the guy well. The NTSB has it all
wrong. I don't know why the engine quit but it was not from a
lack of apex seal oil. The the engine will run for hours without
apex seal oil. I know of one guy that flew from Tennessee to upstate
New York with no oil in the fuel. As far as I know he is still
flying that engine several years later without touching it. Most
people remove the apex seal oil metering pump and mix 2 cycle
oil with the fuel.

As I recall the FAA or NTSB took the engine to  Mazda dealer
that knew nothing about rotaries in aircraft and they
noticed the missing metering pump.

We wrote letters to the NTSB and they just stone walled us on
the subject.