If you enjoy working on and modifying your machine, and becoming ace mechanic in the process, probably the K&N route is for you.
If you’d rather ride your machine than fiddle with its mechanicals, go with the stock components.
Keeping the bike stock means that Honda has done all the engineering for making a bike that’s very streetable. Since the carbs are tuned for the stock components, including the intake and exhaust flow characteristics, changing components may mean re-tuning the carbs. There doesn't seem to be sufficient data widely available for the flow characteristics of the stock components or the aftermarket ones, to predict just what portion of the tuning needs to be changed or how much. So, if you put pods on, for example, it may work fine. Or, you may have to adjust; idle air bleed settings or Idle mixture screws, pilot jets, needle position, needle taper, and/or main jets in the carbs. Or, maybe not. It's try and run, read the plugs, make changes, repeat until you're satisfied (or fed up with the tedium).
You talked about the trumpets, so I'll talk about their importance/function. They are shaped as they are to help maintain laminar flow through the carbs. This, allows even metering by keeping consistent pressures at fuel metering exits into the carb venturi. If this airflow is allowed to go turbulent you can develop low or high pressure gradients at those exits dependant upon air flow rate or throttle setting. This can give you flat spots in your acceleration where the carbs transition from rich to lean and vice versa because of turbulent patterns in the air flow. You've seen a flag wave in the wind. Turbulence from wind deflected by the flag pole exerts alternating low and high pressure areas on each side of the flag causing it move from side to side. As these high and low pressure turbulent rolls travel across the flag, it appears to wave in the breeze. When the wind blows faster, the frequency increases, there are more ripples in the flag wave. The walls of the carburetor venturi are too rigid to wave. But, if air flow becomes turbulent at the mouth of the carb, the same hi/ low alternating pressure ripples extend into the venturi where the jets release fuel. This effects the jet flow, as the rate is determined by a pressure differential on either side of the orifice. Change the suction on a straw, and the flow rate is changed when you sip your drink.
While I haven’t examined a K&N pod, I noticed the UNI pods do not mimic this trumpet at all. In fact, I see nothing that would address any turbulent airflow issues. I have to wonder why Honda addressed the issue but UNI did not? Is UNI’s or K&N’s engineering better than Honda Motor Company?
Apparently a lot of people think so. But, I think Honda got it right on this one.
