I'm sure the motor is not running at top rpm, but I doubt it's weak, or the actual issue based on all the 22 ton huskee splitters I've owned and ran(lots of them, over 30 if I had to guess). But I will pull the air and recoil cover off and check out the linkages because I know something isn't 100% in there, although I'm 99% sure that's not the reason why it's not getting into the second stage.I'll look at my valve this week to see if I have one or two set screws on it. It could be that your motor is not running at top RPM for the job of maybe is getting a bit tired.
I'll pull the cover off the valve too, which way increases the power, turning it in?
Thanks.