Granted this is not about machining but the most concentrated talent on the subject is right here.
I am about to complete an Upshur 2 cyl. 4 strokes, spark engine.
With exception of 2 strokes glow plugs, for which I have hands on knowledge from my CL model airplanes days, all I know is second hand.
Q1. Why my 1962, 2 stroke, 125CC, spark, scooter was doing fine on 2% oil/gasoline mix, but my 6cc glow plug needed 25-30% castor oil/metanol mix?
What I gathered around
-Model 4 strokes run on gasoline, no oil required if you have a wet crancase, but 2% oil wont' hurt.
-Same engine above can run on Metanol
-Metanol runs cooler than gasoline
-Gasoline is a lot more sensitive than Metanol needle setting.
-10% Nitrometane added to Metanol stabilize carburation
-Would Nitrometane added the Gasoline have the same effect?
-Are there 4 strokes glow plug model engines (I never heard of)
What kind of fuel formula you use for slow, low compression, 4 stroke, spark model engines?
Is Metanol available to the hobbist?
Is Nitrometane available?
Thank you for clarifying as many of these questions as you can.
in Austin TX