Wow .. talk about screwy ( not you CRISPYSPA the mounting and the glitch )

Only thing I can think of , is that it had to have a loose connection and was doing metal to metal when inverted .

And sorry ... the older Homies had carb on one side , exhaust on the other ( must be one of the combo Homie/Ryobi engines )

Personal opinion - prop is too large of a diameter ... should drop to a 16 incher - pitch is ok ( I say drop in diameter cause not sure if you can find/buy one and 18 pusher with a lower pitch )

Just out of curiosity .. PLEASE let us know if you get that problem with the right turns again , now that you went back to engine sideways )