I asked a guy on fleabay if a 6hp briggs he is selling would be suitable to replace the 5hp his reply-

quote "hi there....no ....the flywheel is not heavy enough,,,,you could make a heavier pulley or use the Honda GXV160 ...which we have for $495+ frt."

Spoke to a mate last night, years ago I gave hime an old briggs 8hp horizontal, he still has it and said I could have it back.

The thing is I need a vertical. Is it possible to run a horizontal engine vertical? or would there be a problem with lubrication?

This is quickly becoming a pain in the ... !