I talked to a factory rep and he said the 5cc is in the higher comp in the 230?
Ronnydog
Higher compression would usually mean either LESS chamber volume, thinner gaskets, a domed piston, or a bore increase without changing the chamber volume. Doesn't make a lot of sense that they would increase it, but it would be interesting to know if there is a difference in the heads other than the spigots, since the valves seem to be the same. Practically hugging one another,no?
All I gots is TW heads. I don't know. Normally combustion chamber volume isn't added to the published displacement of a motor, but maybe Yamaha is in fact doing the "Spinal Tap" thing.
For those of you who aren't old enough to get the reference:
http://www.youtube.com/watch?v=hN5SCRvhMtk
Spinal Tap was a spoof film about a fictitious rock and roll band. Some of us old farts actually found this entertaining at the time. Go figger.