Originally Posted by Turbodiesel
Plus trying to steer twin tiller arm engines is always a little difficult!
I believe the thing you are after to solve that problem is called T.E.S.T. (Twin Engine Single Tiller) Basically a tiller that also has a couple of short bowdens attatched to allow both throttles to work off one twist grip. Then link engines with aconnectiong bar as you would on a standard twin setup.
I'm suire something similar could be rigged at the lower end of the scale!
Oh, and as for the "twice as heavy" comments, not necessarily. I'm fed up writing it all, so do a search for "Twins" "weight" and my ID. Then go find the brochures for your chosen engine(s). You may be surprised....