porting a vespa
Ok, my stock 50 cc vespa cylinder is off my grande so i can do some cylinder work over the winter. i tried searching already and couldn't come up with much, so here are my questions.
1. I've read that the intake should still be a little rough to help mix the fuel/ air. Is this is the case with the exhaust, or should i make it as smooth as possible so the gasses evacuate the cylinder faster and allow the expansion chamber to work better?
2. what effect does thickening/ thinning the base gasket have on port timing and compression?
3. I've heard of finger ports and how they effect low end. Could I increase low end by lowering the transfer ports, but not cutting them all the way through to the base?
4. The exhaust port has to curve in order to avoid the lower cylinder head bolt. how do i get deeper in there to widen/ smooth out the exhaust port?
5. should I do anything other than widening the exhaust port? (lowering, raising)
6. does it mater if i make a new base gasket out of the papery gasket material instead of metal like the stock one?
7. Any other vespa porting tips short of buying a new cylinder? 50 cc for life!
By the way, I'm running a lightly milled head, a polini mod country pipe, a 13 mm dell'orto, and a mallossi red filter air box, and slightly lightened variator weights on a stock variator (lightened).
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