Gently tap a wooden doweling, or 6" bit of broom handle from the other side, the oil seal that's on this side can stick a bit if it's been in a while, you'll probably find it's caked with oil and grime.
careful with the one or two little metal connection doweling that may be in the middle, take them out first, you don't want them falling into your crank.
6 of one and half dozen of the other Vic, whichever you find easiest to manage, just remember that there is a right and a wrong way as to the way gasket goes on, you should be able to read the 'UP' tag from above, and remember you need to torque the head nuts down too.
Should i put the head on before i put the cyclinder back on the bike?
Personally I wouldnt fit a cylinder head to a barrel thats not on an engine at least. You'll need the cylinder to be held still enough to torque up the head nuts ( 3 stages is best). You'll also have more room to get the cylinder over the piston and slide it down without catching a ring, if you have no head on the top. Another advantage is that with the head off (once the cylinder is in place) you can still lube the bore with a little more 2 stroke oil that might have been wiped away accidently whilst you have been fitting the cylinder.
With regards to the powervalve video. Thats very strange. What revs is it starting to move at? It shouldnt start opening until around 6krpm. Sounds like its open ( the wrong way) long before that.
I dont think it can be, but is the servo motor the right way round? If it was turned the other way round then that would give the same effect as the cables being crossed. Does it do its set up cycle when you turn the ignition on still?
Had a look through a number of videos on youtube and looks like at idle it is not fully closed. Then as the revs increase above idle it closes fully and then only once the revs increase to the point where it is needed ( 6krpm i believe) it starts to open. You'll need to give it a good rev to see if it starts to open again.
2 Very different ways of operating. Strange. The early one seems to make sense to me. stays closed then starts opening at 5krpm then fully around 9-10krpm. Would love to see the 2 compared on a dyno.