Having being side tracked by various members of the forum casting aspertions about the place i live i decided to bring the subject back on track by digging up some more engine facts.
I've looked at Yamaha, Mariner and the new Evinrude E Tec in this case study and based the information against there respective 40 horse powered engines for both 4 stroke and 2 stroke.
Yamaha 40 4 stroke
All three have a 29.4KW output at 5500RPM
Yamaha 40 2 stroke
Again all three have a 29.4KW output at 5500RPM
Mariner 40 4 stroke
40 EFI: 98Kg
40 : 93KG
Mariner 40 2 stroke
40 3cyl 93Kg
40 2cyl 75KG
Evinrude Inline 2 cylinder E-Tec Direct Injection
so this means that for the 4 stokes the Yamaha is the lightest and the Evinrude the heaviest
And for the 2 strokes the the 2 cylinder mariner and the Yamaha 40VMHOS both at 75KG are the lightest, however the Yamaha 2 stroke range are all lighter than the mariner 40 hourse power 3 cylinder.
Maybe its not far to really include the Evinrude statistics in this as the E-Tec is somewhere between a 4 stroke and a 2 stroke ?