Could be evaporated premix dripping off of the stud too, from a carb leak. - For your rev problem... Pull your air cleaner and look if both slides are bottomed out.
Coolant leak is your o-ring on the coolant tube going into the clutch cover. It will allow coolant to leak onto the top of the engine and run through the drain hole and off of one of the lower studs. It will not leak into the trans as long as the side cover gasket is good. Have you had the clutch cover off recently?
And this, an hour and half into the trip home and we get another reason to use all the tools we bring. Changing a leaf spring on the toy-hauler in the Tractor Supply parking lot. I'm not in the pic as I'm the one UNDER the trailer doing all the heavy work.
Was your 125psi compression test after it got hot and sizzled? 5minutes with no coolant is more than enough time to trash the new cylinders and pistons. I'm assuming not OEM cylinders either?