from street knowledge the colt had the 5 hp, and the ranger was only available with a 8hp engine. the original engine would have been white but allot were replaced because they were a pretty crummy engine if not taken care of. rings and valve seats ejecting were the biggest issues Ive heard of.
as to the drive sprocket i know a old bloke with heaps of new old stock and spares so ill give him a call if you like but whether he would part with it for a reasonable price is questionable. otherwise my local mower shop is pretty good for spares like that so ill see what they have. shipping shouldn't be too much seeing as im only on the other side of Melbourne.
regards jay
there was also a bloke on ebay from up Queensland somewhere that had heaps of them and use to scrap them. doesn't know is he is still online tho.
