I got around to building my Chippie, was about to get a TT 91 4C into it but then I came across a literally new YS 110 at a really good price. Any comments about the YS110 in the Chippie? I know the YS is one heck of an engine but then I really do not want to go out and get another 90 sized 4C. Also, I had bought a ST91 ... I am thinking of using that over the YS110. Any comments please ... thanks!