I have a UK Minimax and will probably buy a Meglin carbon prop from the Ukraine. The Arplast prop finally did have a ground strike (must have been close a few times over last ten years!) It was 148 cm / 58 1/4  inch diameter.

Meglin will need to cut down their 161 cm straight prop for me, I'm wondering by how much, I'm a very long way from the plane so I can't just lift the tail and get a feel for the prop disc size

What diameter should be used? Point is, I want to order it and get it delivered before I next see the 'plane. Any info welcome.

The prop dia on my Eros is 63" (2 blader). No probs on ground clearance to date.

Bruce

G-NADS is 60 x 43. Coarse on a 447 but still up in 50yds but cruise is 5100 at 60kts. I'm thinking of going 503 and using the same prop (think it's meant for a 503!).

Thanks each.

Seems we have a happy 63 inch and a happy 60 inch.

There was a standard Newton prop used on most of the (447) UK fleet, was it a 60 x XX? I'm assuming the first number is the diameter in inches.

Mr. Maximum, I wouldn't go for a 503 for the sake of it. I like mine and I'd prefer a 503 over a 447 given the choice, but there's not much in it *overall*.

Antoni, the LAA lists props approved for the 'Max from when it was a permit machine. 60" is the diameter and 43" the pitch. I think I've seen 38 or 40 pitch for the 447. As for engine choice, I did the Rotax 2T maintenance courses many years ago and used to service and repair them. The 503 is a bit more reliable and more plentiful than the 447. I agree that the 447 is more than adequate for the 'Max however and it is lightly loaded in general use on it.

AS spares are now selling for crazy prices, it's time to seek alternative sources. Pistons weren't actually made by Rotax by the way! That is my project right now (along with marketing my M5 (son of M4) Electric Starters, one of which is on my 'Max).

Further to my last post, my prop is 63" x 42" pitch. I had to cut it down from 65" as it was slightly OTT for peak rpm of 6000 when flying. Just reaches those revs now. Engine is MZ202, producing 60hp @ 6k rpm.

Bruce

Max, who made the Rotax pistons?

Right. 60x42 Newton is standard fit for 447. Very slightly overpropped to keep the motor happy. I use a cut down Newton 65 x43 which is around 60" It keeps the revs down to about 5600 in the air and I would like something a little finer but the aircraft is still light on its feet. I regularly see 80 straight and level but it starts to become lively over 75.
Very happy with my non Rotax pistons by the way. Wish that crankshafts were so easy.

Puff, the name of the manufacturer is cast on the inside wall, I can't remember off hand and my 447 is closed up now. If you have one kicking around, take a look. However, Tomshep makes the point that he's using non-approved pistons with no trouble.

I recently blew up my little Yamaha Serow during a long distance trial here in the UK. Pistons for them are hens teeth! I could get a genuine Yamaha piston for around $300 but I spoke with a guy who prepares these bikes for trans continental adventures. His answer? "Buy Chinese, there's nothing wrong with them". He puts his money where his mouth is and he's been trying to destroy his Chinese piston to no avail.

I took his advice and bought one for..... $30! There's no excuse for charging so much for pistons with modern production techniques and advanced metallurgy.