Oops, sorry guys, didn't mean to insult your bikes, what I meant was that
historically, the 750 is the only sohc4 that will be remembered, all the other sohc4's were good bikes for sure, (I had a 350F and it was a great bike) but had no real historical significance, and I hate to see classic CB750's ruined at the hands of would-be "customisers", like I see here quite regularly.
A 718 (WTF is a 718?) smoking a 750? I'm not surprised mate, if you think you're gonna take a little sohc4 engine (it started as a 500, then 550, 650 etc, but the bottom end and transmission was only designed to handle the moderate power of a 500 ?) that far from it's original design brief with any hint of reliability, you're gonna be so disappointed.
It may well beat a 750 (same as a 750 would blow it right off the road with the 1060cc Cobra engine) but most of the "smoke" will be coming from your engine and gearbox, ha ha! Cheers, Terry.