Borriss - I am just in the throws of building my Senior Kadet [15 - 20 year old kitset, 3 channels] and my son will make me a carbon fibre undercarriage [tail dragger]. So it will be in its original form apart from the undercarriage. I have an OS 52S four stroke [old and unused], an OS Max 46AX [unused] and an ABC Supersport SC 61A MK11. I am tempted to use the OS 52 for quietness and larger prop etc. Non of these engines have been used. I would welcome some advise please. I seem to be a little late in joining this thread. thanks in anticipation