I dunno much about the 650 engine.
But the 750 is a very popular engine with minimum maintanance and it is supposed to last FOREVER.
I actually have only 3,000 miles on mine.... but I am a member on 2 CB-750 forums (actually, yahoo groups) and there are people with more mileage on their original 750 than I have on my contour !!!
by the way, join the group and post your question !! I am sure people would answer you with details on these bikes...
Regarding the size, 750cc is not that big. I actually came from a 535cc to a 750cc and I am just starting to think the bike is too small (which it is not, the CB750 is a VERY NICE size bike, but once you get used to it that is it...)
ooops... that would be ur first bike correct ???
Get something smaller.... I would even recommend you to get a Vtwin cruiser....less dangerous... those CB750 turn around 9,000RPM and that is the DEVIL CALLING YOU....you better get a smaller v-twin cruiser... much less RPM and you wouldnt be tempted to accelerate the bike.
