MinnFlyer

Liquids ARE compressable, but not to any noticeable extent under ordinary pressures.

The cylinder would not likely be 100% full of fuel - the piston wouldn't move at all. Most probably, it would have both liquid fuel and air.

Good point on making sure that the glow plug is disconnected before turning over by hand! Although it is unlikely to kick too hard if you have a firm grip on the prop, why take a chance - REMOVE THE GLOW IGNITOR.

Regarding the removal of the plug vs letting the fuel run out the muffler, I have found that it is often difficult to get all of the fuel out this way. Although I have done it both ways, I have better luck removing the plug, draining the cylinder by inverting and flipping the prop and then giving it a spin with the starter. BE CAREFUL - fuel will spray out of the glow plug hole when you hit it with the starter.

I guess the message is the same; make sure that the engine is not hydrolocked before you start the engine. It is particularly important if you are using an electric starter instead of a chicken stick - very easy to ruin a good engine.

Ross