You are on crack with your desk top caculations. Real world coming from a guy that used to ride a 4 stroke turbo and now would only buy two strokes . The only place for todays 4 stroke sleds is going straight up a mountain at full boost making thunderstruck vid's. Besides that they suck. Don't get me wrong I could make a 4 stroke work, but they just beat the hell out of you comparared to a 2 stroke. Yamaha's feet are stuck in the mud and they are missing the boat. I do see a real potential for them to be ground breaking but it is in the snow bike market. They have the technology, just put it to use. They would sell the hell out of them if the had the first factory produced snow bike.
Ya, NOT SO MUCH in the real world.
Polaris Pro 162 800 RMK
Wet Weight 493lbs
Horsepower 160 (2015 model at sea level)
Power to weight ratio = 3.08lbs per HP
(I list this just for base comparison, NO ONE is going to seriously ride a normally aspirated 4S Viper in the mountains, while the overwhelming majority of 2S riders do ride without a turbo. I am trying to honestly compare apples to apples here..I make NO argument that a boosted 2S will win until its engine fails)
Yamaha Viper 162
Wet weight = 595lbs (this is the only number we have so far)
Horsepower 125
Power to weight ratio = 4.76lbs per HP
Yamaha Viper 162 with OEM Turbo 6lbs Boost
Wet weight = 610lbs
Horsepower 180 (at all elevations)
Power to weight ratio = 3.38lbs per HP
Now lets take these two sleds up into the mountains and ride them at
6,000ft.
Polaris Pro 162 800 RMK
Wet Weight 493lbs
Horsepower 132
Power to weight ratio = 3.73lbs per HP
8,000ft
Polaris Pro 162 800 RMK
Wet Weight 493lbs
Horsepower 121
Power to weight ratio = 4.07lbs per HP