Motor Glider engines - Rotax 535 spares

I fly a Nimbus 4DM motor glider, owned by a syndicate that operates
out of Lasham, UK. A breathtaking machine, particularly when I
compare it to gliders I flew decades ago such as the Grunau, Olympia
(Meise), and then the Skylark series. But I digress ...

This post on the international soaring newsgroup is to seek advice on
spares and servicing for our engine. As an early 4DM it has the
Austrian Bombardier Rotax 535C 59hp water-cooled two-stroke. Later
4DM models have the Solo 2626-2.

The problem is that Rotax no longer produce or support the 535C, or, I
believe, the complete 535 series and some others used in Motor
Gliders. The 4DM Rotax can be changed to the Solo at Schempp's
factory but this is time-consuming and expensive. Since our Rotax is
running OK at the moment it seems unnecessary.

However, we are worried about future spares and servicing for the
Rotax 535. It is also fitted to other motor gliders and microlights,
so several hundred of these engines must exist, presumably most in
Germany. We are aware that the Walter Binder company in Germany has
LBA approval for servicing Rotax 535 engines, and have had good
service from Binder in the past. However, we understand that there
may be a difficulty with some spares, in particular Trigger and
Charging coils and the engine "back plate" that carries critical
parts.

Since this newsgroup is widely read, and there must be some hundreds
of Rotax engines no longer supported by Rotax itself, but still in
use, we wondered how other owners are dealing with the situation. It
must be possible to have critical spares manufactured or supplied from
sources other than the original manufacturer, but these must have
regulatory authority approval and be fitted by an authorised engine
repairer.

Any ideas? Perhaps there is a more relevant newsgroup or owners forum
to pursue this issue, maybe in Germany. If so, please email me on
, but bear in mind that I will be partially out
of action next week, at the annual FAI General Conference at which I
and other IGC people (for instance Bob Henderson, Tor Johannessen,
Roland Stuck, Bernald Smith) will be representing world Gliding
interests.

Sorry to bother the rest of you on this matter of detail.

Ian Strachan
Lasham Gliding Centre, UK