ORIGINAL: mpascual
Like Saito small gas engines ? The FG36 (36cc) does not have needle bearings on the con-rod.
Like oldies spark plug small engines ?
On a 4 Stroke engine the amount of fuel (with oil) is smaller than a 2S engine and oil-fuel flow mix does not goes directly to crankcase (and con-rod) as 2S does.
Lubricity of gas(petrol) is much more than methanol.
I've count the needles on a small needle bearing availables today (caged), and the contact surface with the crankshaft pin is so small and can cause more troubles than a plain bushing.
Only my experience.
Best regards
Whilst I do applaud Michaels attempts to creat something attractive to part of the market by making it a little diufferent to the myriad of other offerings fom his countrymen, He has not done to well so far in making his offerings anywhere near to decent for regular flight over an extended number of flying days.
A couple of things about your post
Comparing anything of Michaels creation to a Saito is quite an insult to Saito
The "Oldy" engines to which you refer also ran high oil QTY in their fuel.
I never realised the NGH 9cc was a 4 stroke - why even compare it to one? On a 4 stroke, the heat input is also for half the revolutions of a 2 stroke.
Michaels creations to date have a long history of early crankpin / bushing failures - that is called the proof in the pudding.