I have a Vespa Grande (30 mph version), Techno pipe and a malossi air box...everything else is stock. It runs great but it seems that once the speed gets below 28 or so, it really tanks. I removed 2 of the roller weights and the RPMs stay high and holds the speed much better. I did not want to leave this way the 2 weights missing so I figured that if I drilled out each weight I can get back to the 3 weights version. I started drilling out the weights (slowly increasing the size) but its still variates too early. I actually have the brass weights drilled to the point where its more or less a thin tube, but I still cannot get to the 3 weight version that works. Any thoughts? Am I on the right track? I figured that slowly drilling out the brass in steps I could get there...wrong. Help?