I have a MKII pump on my 1.6 N/A Vanagon which I bought from a mechanic's back shelf. As I approach the high end of the rev range (just before the factory shift mark) it starts pouring out extra smoke. I don't get a drop in power (obviously). This is a strong running little pump which doesn't act like the original which got weaker at the high end. I don't know the history of the pump, does this sound like it has already had a governor mod done to it, with a burst of extra fuel at high rpm's?