Cheers.
They are called Etec's and have already been made and are fast becoming a very popular choice here in Australia. Just an example of how good they are on fuel- A local fisho got 131 kilometres out of 60 Litres on a 130HP ETec on a 5.4m fibreglass boat. Pretty impressive if you ask me!
For more information on them-
http://www.evinrude.com/en-US/
I have only ever owned 2 stroke bikes. Dont think I will be ready for dark side anytime soon! I have a road registered Yz250wr. Basically a YZ250 which has bare essentials to get it rego'ed in australia. Feels pretty cool riding it down the road legally!
Here is what it is-
http://www.yamaha-motor.com.au/motor...6&modelcatid=5