Info for Tim from Geb.
Hi Tim, I have done some research on your MDS engine. It looks to me that it is an MDS15FR model.
To run in, use 80/20 (Methanol/Castor oil) straight fuel. Run in without pipe on for 15 runs beginning with 3 runs of 30 seconds - leaving to cool down between each run. After the first 3 runs you can extend the time slowly each run up to to 1 minute - letting it cool down between each run. Start with a 4.7 x 4.7 prop. After 10-12 runs mount the pipe and give it a few more runs. By this stage it should be loose. Recommended plug is a Rossi No.6. After this you can go to an APC 5 x 5 prop. It is said it should reach 30,000rpm with this setup. Don't load it up with too big a prop - it could damage the conrod. Ripmax advertise that they stock spares for this engine on their website.
Look at this webpage (its in German but google will translate it for you!!
http://www.rc-network.de/forum/showthre ... 9-MDS-15FR