Nova, have you figured what the problem was? I've been having the same issues as of late. I can rev up, and when I let the clutch go, it slooowly ges going. The engine revs up, then down, and then back up again. My plugs were old, so I changed them, and that helped a little. I'm thinking of maybe the fuel pump as well... it's never been changed, as far as I know...