i had cmb .21 years ago seems they still do this. i think its good but the material still not up to what NR uses but anyway- plenty of WD40 inside and rock the engine back n forth/turn it over ,play with it a while (maybe while havin a beer /watchin tv . then just hold it flywheel up and rock it around tdc area and maybe use a thumb to coax the rod down ,do that for a bit ,it comes off.
i wouldnt do anything drastic would only cause undue wear,jus gotta b patient .
another way (had to do this with cmb evo 67/80 and some other .80’s back in the last millennium) ,make pull sleeve out,make sure theres no metal filings,take the flashing off ports if needed ,put it back in,drop it in a boat and start it real rich n let it idle for 30 sec. do it a couple times. or even just spin it with starter while spraying oil in carb for 10 sec bursts a few times will do the trick.
ahhh miss the days when everybodys .80 class engine had a “wicked tight spot” and if you didnt hand lap it ,they would randomly stick while trying to start. you would HAVE to use a spanner on the collet to move it off tdc and you would hear the squeak lolol good times……good times
