So this Sunday I was seriously emasculated on the ride. Even the STOCK peds were showing me up. Granted I'm hauling the equivalent of two average riders, but I would think the performance gap would be smaller than it was, having a 14.12, 12 intake and expansion exhaust.
So I am taking two approaches. I want to get new rings. The current ones might be okay, but I have no idea what the history is on them, so I figure better to replace and just get it over with. The other approach is to bore out my intake and ports.
I grabbed my 12 mm intake and took some measurements, to make sure I would have enough material to bore it out to 14. I couldn't get my hands on a true 14 mm bit, but a 9/16 bit reads as 14.2 mm on a caliper, and I figured that was close enough. I put the intake in a vice and used a cordless drill (explaination below, please don't flame me) and went _SLOWLY_ , ~100-200 rpms. I went through a progression of bits, slowly boring on up to the size I would finish with. I would be taking too large a bite with using the finishing bit right away, might lose control of the drill or ruin the intake.
I like the results of my handiwork. The resulting interior is a little rough from using a handheld drill, which should help with atomization. I tried clamping it in a drill press, but I just couldn't get it to sit securely. I know this sort of thing can only be done with intakes that have straight runs like stock Minarelli intakes, but it gives you an idea of how to do it if you are as bold (and cheap) as I am.