Joe, rotating the engine on the stand helps accelerate the bedding in of the lower cylinders. You would need 1 tank per cylinder (0.5lt). Max safe No.1 temps are about 200C, but beware of the IR thermometers - that are not accurate! Best if you only trust the contact probe.
In your shoes, I would take out the plugs and check them for fouling and/or gaps. Finally, you should reset the valves after about this time, the initial wear spoils the gapping there as well. Just make sure you are at the TDC of the firing cycle when adjusting (as opposed to the TDC of the exhaust cycle).
Do all that, then try to tune the engine by temps @ 75% throttle until there is no cylinder dropouts and go fly. Oh, and by the way, check your ignition battery can provide all the current necessary at high rpm settings (there is a firing pulse at all 3 cylinders per engine turn!). If using a NiCD, consider switching to a LiPo just to check - misfires can also occur due to the ignition.
BR,
Hector.
Last edited by hpergm; 10-12-2016 at 01:25 PM.