ORIGINAL: Motorboy
ORIGINAL: Luna_Rendezvous
I believe there is more compression because the cam timing is different when rotated slowly in the opposite direction, have only noticed this in 4 strokes.
Mike.
Not whole correct answered..
More compression in 4 stroke engine are due by the piston goes from TDC to BDC, therefore the engine get better cylinder filling.
The 2 stroke engine has poor cylinder filling than a 4 stroke engine due difficult to fill the cylinder by crankcase pressure..
You have lost me??? We are talking about rotating the crank by hand, so if there is any pressure difference in a two stroke, then atmospheric pressure will balance it through the exhaust port.
In a normally running 2 stroke, then I agree with your 2nd statement.