Hi Bill.

 I recommend you to contact Yuriy Yatsenko. He is sometimes a bit slow in replying but you just have to keep bombing him with emails. His contact information can be found from their website. In near future, the Discovery website will also have detailed instructions how to set up & operate Retro engines.
 On the other hand, secondary parts, like the prop driver, can easily be made by someone who can operate a lathe, maybe not worth the trouble to try to source them from Ukraine.
 From the information that you get on discussion forums, I think about 12% is good. Mostly the users with problems just try to invent their own way to operate the engine, without understanding that to get the best out of it, the only way is to follow religiously the maker's instructions to set the running parameters right.
 Unfortunately there is also some earlier series with some quality issues that can cause problems in running.
 I may be able to offer help too, please Email me or send a PM.

 Lauri

   This is the problem - instead of getting parts, you have someone make them? If you took a drawing to a machine shop to make such a thing, the cost would be astronomical and there would be a good chance it would be wrong. To ensure success you would need to take it to a specialty machine shop, still more expensive. A custom one-off part with the required tolerances would be, I would guess, $500 minimum, maybe a lot more depending on whether a CAD drawing and CAM machine programming was required.

   That's one reason I never got involved with the Retros, even though I am impressed with the performance. No reliable suppliers, including (no offense) the Yatsenkos themselves.

    Brett

 Bill,

 The correct pitch is about 6, depending on various things. Maybe the new ones are 5,9, I don't remember exactly. But it doesn't matter as the props can easily be tweaked to a new pitch (heat & tweak works also with wooden props if you know what you are doing).
 The old generation props were raw milled quite roughly and then the airfoils were hand finished. Because of that, the repeatability was not so good; it was allways a small catastroph if a good prop was broken. The new ones are a million times better, both in efficiency and repeatability.
 It is not recommended to use carbon props, they are too heavy for the engine.  You may even break the shaft with one. I know that Brian E. made carbon copies of Andrei's paddle-blade prop but I understand that it was made for electric power. I've tried them with Retro and I did not like them.
 If it goes too difficult otherwise, I can make you a prop driver. (if you're not in extreme hurry with it..). It can be a std one, or a monolith with spinner backplate if you send me the cone. L

Getting back to making rather than buying, I suppose that here in Oz we are lucky enough to have a great percentage of fliers with fitting and turning skills and it is absolutely no problem for them to machine something where possible - in fact its a badge of honor to do so!

Bill, if you 'need' a custom prop drive washer and you need it done right there are guys here that live and breath this stuff.

Thanks.