I seem to be having problems getting this engine running correctly. Bought new and run in nice and rich using straight 20% castor on a 16 x 8. Thought I'd done it all fine but I don't seem to get the RPM quoted (8000 - 9000), flat out gives around 7500 and the engine appears to run hot? I've changed the plug for an OS A5 as recommended. Engine has run for probably around 2 to 3 hours now so I would have thought it should peak out by now?
Also what prop size should I aim for to get max power rather than speed? Son wants to prop hang rather than get top speed out of it.
Any suggestions most welcome.
TIA
cheers, Len