I know that this is full size but you may find it interesting.
All German WW2 turbine engines were started by the very small compact Riedel starter, a 2 stroke air-cooled twin cylinder engine sited in the bullet fairing of the intake of the jet. They made around 8000 of these little engines and they often ended up in museums and go carts.
The small petrol engine was started by either using the pull handle or by the 24v electric starter. This meant that the plane did not need a service vehicle to start the engine. The little engine uses case pressure to case pressure to push a piston backwards sending the dog clutch to engage with the front of the turbine shaft.
This is an amazing little engine and has many rolling surfaces with roller bearings. The electric starter motor for example has a simple ball race at the front but at the back there is small roller bearings and a very small epicyclic gearbox. The starter gear grabs onto the shaft by means of a one way sprag clutch. The flywheel has balls in galleries that are thrown out by centrifugal force and they exert force on the wet clutch to engage the rear gearbox which is also epicyclic.
Over a year ago now I managed to find a Me 262 starter motor from a motor bike dealer in the Netherlands. However it had many parts missing and it became obvious that it had been dropped early in its life and damaged and then robbed of parts. I spent many hours making the missing ignition system , the carburettor and the piston and dog clutch. I now have it all screwed together and have it running for the first time. The one good thing was the engine had hardly been run at all. There was no sign of wear in the bore of the one cylinder I took out. The bad part is that there is very high compression and it is quite a job to turn it over! I know nothing about 2 strokes and have learned a lot. Fortunately there is a Bernd Sobek who is the world expert in them and has several running who has helped me . Roger Emms also helped me with 2 stroke information and assist in getting it started.
http://www.youtube.com/watch?v=BGUqV0dl9gA
John