Just a little bit faster...

[rhetoric]

I'm into a scooter for the gas mileage. But I also bought a 150cc because I want to be able to keep up with traffic on my commute. My Roketa has 80 miles on it and looks like I'm getting 54 mph on the flat and that's pretty good, but I sure wouldn't mind doing 60. Just enough to feel like I'm not holding up traffic on the stretch of 55mph highway on my commute.

Based on what I'm reading I've seen several ways to boost performance a bit (loose 25 more pounds, performance CDI, valve clearances, wait till I've broken the engine in a bit more, etc.).

So, what's the easiest way to boost my speed just a bit. I don't want to turn it into a race scooter and I don't want a 250. What's the strategery?

[prodigit]

First of all, don't go WOT on an engine that is still in the break-in time.
You'll ruin the engine, giving it an early retirement.

it takes on average about 500 miles on city riding before the engine opens up a bit.
Do regular oil changes.
After a good 1000km the engine will feel much smoother, the sliders will wear some, allowing the engine to rev higher.

But 55-60MPH is about the max you can get out of a 150cc.

If your scoot recycles the exhaust gasses, get that EGR out, and re-jet your carburetor. Usually that could account for ~5MPH higher top speed.

Do one modification at a time, test thoroughly, and think before installing any other mod. Not all mods that are labeled 'performance' make your scoot run better.

[qwertydude]

BBK and rejet the carb is the only real way to get significant power gains. The rest of your speed is mostly determined by getting the power to the ground effectively which means CVT upgrades. CVT and BBK upgrades are all you'd realistically need to do to get the most speed for the least money. And after that you're talking investing a lot more money, likely enough to get you a 250cc in the first place, for not much increase in performance and a big hit in reliability and longevity which the 250cc will at least give you.

Not to mention keep bolting on performance stuff and the engine will likely guzzle more gas than a 250cc scooter because tuning the crap out of an engine to get performance ALWAYS takes a bigger hit to mpg than just getting a less stressed engine in the first place capable of making the power reliably. This is best shown with two italian scooters which don't get the ultra modded treatment. In this case the Piaggio Fly 150 and the Scarabeo 250. Both get right around 60 mpg the Scarabeo manages to get the same mpg because the engine is not as wound up and stressed so it actually uses less fuel.

CDI, intake and exhaust put together don't even give you the power gains from a BBK. But the engine already is being pushed to the limit. The GY6 design is naturally a 125cc design so we're technically already on the BBK size range for the crank. Increasing the power will dramatically shorten engine life.