4 stroke airbox Mod

I stumbled upon a quick and easy performance boost for the 49cc Honda clone engines. The stock air cleaner inlet is very restrictive, and was causing my engine to bog and hesitate at midrange rpms. I resolved this by simply enlarging the inlet with an exacto knife. I only needed to expand the inlet by about 1/8" across before the engine began to idle more smoothly. Now it runs like a champ. The only downside to this is it made the engine a bit louder, if you consider that a problem.

Now, if only I could figure out a way to hush the gearbox whine...

Nice...that's a major improvement on the stock airbox. I'm a fan of the retro look as well.

Is your airbox from one of the small russian engines? I removed the red cowling from my engine, and it looks much better...less like a lawn mower

Opening up the intake has really made a difference on my bike. I love riding it now. The gear whine is either quietening down or maybe I'm just getting used to it.

Anyway, I'm becoming a fan of these 4 strokers.

That's awesome..motorbikers sure are resourceful. Do you have any suggestions for improvising a fuel tank?