Billet is nice, you can sometimes cut them open more and not lose too much integrity. The 3.2 ounces is a bit low per gallon, 4 is usually best unless you have some really good oil.
Is your filter clogged with oil? Probably not since so new. So if you aren't getting a good top speed then maybe you need a smaller jet. Does it start to cut out at the top speed and sound kind of choked up?
Pull the spark plug out if it's been in a while and just look at it a bit, white, brown or dark ceramic? Do you see black oil around the head at all on the outside?
Compression testers are available for free to rent at autozones and such. You pay them, use the tool, bring it back and get all your money back. You could do it all in 5 minutes right at the store's doorstep. Maybe even the people behind the counter will walk out with you if you mention it's a motorized bike and that it's just outside the door instead if going through the entire register process, some people really think they are cool and would rather save companies' time by shortening how much time gets spent doing the same thing logistically and satisfying their own curiosity at the same time. I'd give it a shot and at least you'll get an idea of what could be going on related to the power issue, also faster and cheaper than trying to upgrade your speed with an intake manifold.