Hi there, an other good theory!,but I never had any temperature problems, there are not many choices on propellers Im stuck with the 17x6 on the Goldwings MX2, tried a 18x6 once and engine stalled at some point, And I thik it was temperature, you have to wear the alloy engine mount and is good to use some pc proccesor paste were they meets,to help to transfer the heat, Still using the sandard ignition with a 6v pack and the metal cap removed,just the silicone plug and the mesh atattched to the engine as ground.
being flying the last year with no problems at all,just an ocasional caugh when cold, thats it, the low end is on the rich side, so when hot it idles ok but if living it idling for too long it gets reach and if you leave it it stops, behaves the same way as a glow, so is good to keep punching the throtle up to keep the engine warm if you have plans to take off again.
What I done to help with the heat is made with thin alloy a kind of scoop,which goes sandwiched beatween the engine and the mount goes over the carburettor and again on the other mount in a kind of cone shape.and maches with the cowl intake vents,so it hepls get riding of the heat and forces some air in the back of the engine were the carb is, carb is so close to the engine and in the back, I guess it gets very warm back there. will post some pictures.
My engine seems to be on the cold side, and it takes a good 3 or 4 minutes in the air to warm up and reach peak power
Oviously being saito glow-petrol conversion, they should made an other head to get rid of the heat,and use roller bearings on the conrod to be able to use less oil.
Is a very nice engine, I love its sound and the power at less rpm, and those nice shinny rocker covers! harley davison style
but still too expensive to have those problems, had two chinesse engines since the same time, and they are running untouched 0 problem since new.
Times are changing and now there are several new brands, I found an interesting section in the justengines uk website, they are selling a new variety of very cheap small gas engines which looks like glow conversions, they uses 20:1 oil mix so still using bushes in the conrod, but it gives you the chance to fly smaller planes with gas,avoiding mucking your plane up and gives better and consistent idle
keep posting news and experiences!!