Thanks for the comments Sam, had to change employment so not much time for the hobby recently. The ST 4500 deal fell through, but I did get a bargain on a new OS BX-1 35cc. More questions on the engine, why is there a very neatly drilled hole in the centre of the piston? And will I potentially still have engine cut out problems with this engine inverted? I like the idea of not having to cut the cowl too much (or at all) with these 2 stroke engines. Would it help to have a fuel pump for this motor?

Completely different questions, what torque values should the servers have. There will be a total of 8 servos.

2 for the ailerons
2 for the flaps
1 for the rudder
1 for the elevator
1 for the throttle,
1 for the U/C

The retracts are air operated, supplied from PICA while they still were in business.

Regards,

Alan