ORIGINAL: ameyam
2) Then take off the backplate and the carb: easy enough to do that. Dont take off the head yet. Now check in both if there is any grit. If there is none, chances are you goy away without any internal grit.
Just take care with that... if dirt made it into the carb, it also made it inside the engine as the prop shaft has a cutout for the intake air.
Removing the backplate and flushing the engine with water first helps this.
Note I suggest WATER not Glow Fuel/Methanol FIRST.
Methanol can actually cause the particles to somewhat stick to the engine sides, making it harder to flush them out... while water tends to dissolve and carry away most dirt like debris.
ORIGINAL: ameyam
3) If everything is OK, take the glow plug off and immerse for a couple of days in plain methanol. Methanol will slowly remove any dirt and also any gunking
It will not remove dirt by itself. It will however dissolve oil based stuff, but any dirt in the plug element area MAY stay there.
Usually I don't bother with the glow plug, I just replace it after a crash.
ORIGINAL: ameyam
I am not suggesting to open the head as that will spoil the gasket. I have lost a 55AX that way. Avoid it but if your engine has grit inside go ahead and open it.
Agreed. Removing the head is often not necessary, especially if you do not feel grit as you crank the cylinder.
Also you can remove dirt from the cylinder head simply by flushing water through it ( glow plug removed too ) with the muffler off, and the exhaust port open as far as it will go.
I've cleaned a couple of engines this way w/o having to pull the head.
The head may be pulled if you suspect scoring of the liner or cylinder.