Nige,

I picked up an MDS .48 at a swap meet from a fellow who gave up on it. The price was right and I took it on as a challenge. Read all the posts for advice and did the following:

1. Mixed my own fuel 21% castor oil, 79% methanol.
2. Sealed the carb with RTV, expecially around the funky two piece carb hold down bolt.
3. Installed a Fox shielded glow plug.
4. Installed the engine on a trainer, gas tank cushioned, with middle of tank 1/4" below carb needle.
5. Used 11/7 prop.
6. Took off rich and watched it lean out in flight.
7. Slowed engine down when it sounded like it was getting hot.
8. After about four hours of flight time, the engine in now fully broken in and operates reliably. No flameouts with excelletn transition from low to high.
9. Compression is excellent and starts at one or two flips of the prop after prime when cold or hot.
10.The MDS .48 is the most challenging of the MDS line, definitely not recommended for the beginning pilot or anyone who expects to mount a new engine in his plane and fly after running one or two tankfuls on the ground. It requires patience and an experienced ear for tuning.
11.Since the first one, I have acquired three additional MDS .48's, one MDS .40, two MDS .68's and three MDS 1.48's all slightly used, from modelers who couldn't wait to get rid of them at swap meets. The other sizes have been less challenging to break in and get to run right. The 1.48's have the C-2 carbs. The others have the original carbs which are tunable.