MS211 oil pump seating issue

[someguy1942]

on the MS211 stihl chainsaw how can u know for sure u have the oil pump installed at the correct depth so that the its hole lines up with the hole in the housing that receives the lube? many youtube videos say to simply push the oil pump in until it won't go any further but when i did that, it clearly wasn't in the correct position given the oil pump gear wasn't properly lined up with the worm gear that drives it. i've read in various posts that stihl chainsaws have a "shoulder" that makes getting the proper depth easy but this isn't the case with this model chainsaw. please help if u know what i'm missing here. i can't imagine stihl would engineer this in a way where the pump could slip out of position from years of vibration from the work it's doing but without a "shoulder" or something, it seems the pump could do just that.

[sablatnic]

I measure from a feature on the saw before pulling out the pump. After cleaning or replacement I press (normally with a hammer) the pump back in to the same depth. I cannot remember it hasn't worked.
The pump has to be turned correctly, look for the marks around the hole.
The pump is pulled out, and hammered back in, with a m5 bolt in the center hole of the pump.

[someguy1942]

SOLVED: so for anyone reading this post down the road, i wanted to tell u what happened so maybe it would provide u with a clue. the local chainsaw repair "pro" got my chainsaw oil lube flowing again - all he did was take the oil cap off and put it on its side for 20 mins. said it was "air locked" which i guess happens when u take it all apart to figure out why it wasn't oiling the bar/chain in the 1st place. sounds like i fixed the original problem but in doing so, created this odd secondary "air lock" problem that none of the youtubers nor anyone online mentioned could happen when u introduce air into the oil's pathway. i'm a little confused why this wouldn't happen anytime u're out cutting wood and run out of oil in your reserve tank. maybe someone can explain that.....