I bought a used TT Pro .46 and we don't know much about the engine. It uses a single needle valve. Can someone give me an idea how old this style of TT Pro is, and any other bits of info on it? It seems to be touchy to tune, but ran great yesterday after a lot of tuning by someone more experienced than I am. I'm very interested in any particulars on it and would like to download the engine manual if it were available anywhere. Thanks.