My Polini exhaust finally came. It is suppose to be for a Vespa Grande but it fits on the TFR and all the specs for the grande and TFR seem to be the same from the research i have done. The pipe is on there secure and the plug chop i did this afternoon showed light brow/dark tan. My problem is the acceleration really sucks ass now, the top end rocks though. Another thing to factor in is that my piston has scorching marks on it from the previous using straight gas not oil. This never hurt the perfromance before, although the acceleration has always been a little slugish but thats usually normal for kinetics. Anyways if decreation in acceleration is normal with tuned pipes then is there anything i can do to bring back up to spec or if this is not normal then hopefully u guys can give me some clues to the problem. Thanks alot in advance.