How many of you guys have ever used a ported head, or even better a ported head with a port matched intake?
The results on a GY6 are astounding, add an A-9 cam, and you'll think you strapped on an extra 100cc. It isn't really hard, but it can be time consuming, and having all the right bits and burs for getting inside tose tiny ports can be a real bear, but if you haven't tried it...you should!
Bolting on parts, BBK, cams, exhaust, ignition...all work, we know that, but what is really missing is the
smooth delivery of that fuel/air mixture to the combustion chamber, and the unrestricted removal of the exhaust...