on the side of the engine it says SC and on the other says 75. but looking through loads of pics it looks like an aps 75. the main problem is it dont run i bought a new glow plug and now it starts but cuts out after 30 seconds or if i give it a bit of throtle. Ive came to the conclusion that it need to be tuned but dont know how please help me i was hopeing to fly today as it is my day off work.

The best answer is by :
balsaman :
Is it your first engine ? in which case I recommend going to our RCME site where you can see all the threads for beginners .Alternatively try asking more specific questions Will try to help with my 50 years of experience.Myron.Yes there is little difference between SC & APS I believe .Open up the throttle to about to 2/1/2 turns or more to start with/ Sounds to me it's running too weak & possibly overheating .especially if it's not yet "run-in".