Matt Whiting wrote:

Why? the trouble has never been that one of our Rotax powered engines
quit because it failed from over excursion. Not one Rotax in a Mini-500
failed from the engine wearing out, ever. The only failures that ever
occurred was from failure to jet the engine according to instructions,
using poor fuel below 86 octane, or running out of fuel, or improper
coolant mix or leak, but never the fault of the engine. Nothing beats
the power to weight of a 2-stroke and the ease of maintenance. It was
the right engine.

So where is this the fault of the designer or the aircraft? It was made
plan in instructions, AD's and advisories not to make these mistakes. We
flew the factory helicopters hundreds of hours to prove the design
worked. Sure there were some development problems, but each one was
solved and made available. The truth is that the engine worked well.

Like it or not, your comments are unfounded, uninformed, based on lack
of experience and unappreciated.

Dennis Fetters



Sorry, but that isn't correct. I ran two-stroke motorcycles for years
with no problems. Many outboard engines are two-strokes and they have
excellent reliability records. I think the issues with two-strokes in
aviation has been improper operation.

Matt


Well, sorry Matt, but my statements are right on. In fact, you just
helped support exactly what I said. Thank you.

You see, the majority of people buy a motorcycle ready to run, set up
correctly by the factory. Same as outboard engines, they're already in
the boat and set up by the factory. As I said, if you have proper
installation the 2 stroke runs without problems.

On kit built aircraft, nearly all of the engines are installed by the
public, never by the factory. And nearly all of the engines installed in
kit built aircraft are done so not according to factory instructions, or
improper factory installations. So they have a higher rate of failure.

2 strokes are very much in aviation, and will be for a long time.

So again, thank you for helping make my point, couldn't have done better
myself.

Sincerely,

Dennis Fetters