RE: Kaos 40 - old timers used what engine
The MVVS engines can be set up as either side exhaust or rear exhaust. The engines are delivered with right hand exhaust but before running you can disassemble and reassemble as rear exhaust. Once it's been run you have to leave it that way.
I don't know if they can be set up as either left, right or rear exhaust or if it's just right or rear exhaust. I'd bet they can do all three. It would be worth a phone call or e-mail to find out.
Dave