I would not beat. Don’t ask me how I know. Besides, anything you have to beat on to free up will more than likely be unusable anyway. Try evey concoction you can learn about and yes, try heat. I have had a twin powerhead soaking for a year now—nothing. I use auto trans fluid and acetone (50/50). It should be completely submerged in your choice of penetrating elixir.
Have also heard of cooking in a crock pot for some time. Worth a try. I firmly believe freeing up stuck parts is all about the freeze/thaw cycle. I have always wanted to cook a stuck piwer gead in an oven then transfer it to a freezer over and over. If I were a bachelor I would have tried it already.
Have also tried tapping ever so gently with a metal rod through the plug hole on the top of the piston and I believe it has helped in the motors I’ve unstuck. Again, carefully and gently.
But patience is key. The thing wants you to beat your will into it. It wants to exploit your stubbornness. Don’t let it.
It looks like the flywheel/mag is still on?
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