is it possable

i have a murry mower with a 18 hp twin and a 6 speed transaxle and i have had a pully change done to it and i was wondering if i could make it chaine drive i have a motor cycle motor i want to put on it and i hav the rear wheel and i was wonder if its possable to take the trans axle apart and get the axels out and weld them to the hub on the motor cycle wheel and make it work and use part of the housing where the axle bolts to the fram on the mower and use those on the axles to reattach the whole thing back to the mower any help would be helpful thanks