yamaha g8 to gas

[yamahag8]

i am converting my yamaha g8 electric to gas by using a 15.5 verctial motor conected to a old john deere tranny with 1.2nd,3rd, and most importantly revirse i was wondering what sprockets should be used also i am still using the orangial diff from the cart

 

[EEngineering]

A vertical shaft engine would be very hard to use. Although it may be possible,
But I would recommend a side/horizontal shaft engine. It will make your build much easier.