To add my backwards starting experiences, I like the engine to be really wet and then flip it backwards whether 2 stroke or 4 stroke. If not wet enough it will follow on through and start in the direction you are flipping it.... Now if you are normally a frontwards flipping guy and the engine is overprimed it's going to want to start backwards. Being overprimed (or really wet) raises the compression ratio to the point where the engine isn't going to want to go past TDC, therefore when it fires it will be well before TDC and want to fire in the opposite direction.

Ernie