Yeah, the micro porous check ball allows air to travel to tank freely and is supposed to limit the rate of evaporation to the canister. It has a small affect on HC emissions that is too small for me to care about, and if removed will make it a little easier to flow fuel to the canister. The micro porous ball plugs all the time. The effect on flowing fuel to the canister is only relevant to people who habitually put 4.5 gallons of fuel in a 4.2 gallon tank.
The canister filters air going to the tank AND stores HC emissions. A bike sitting on the sun or riding down the road will emit FAR more HC then a car because the tank is exposed to the sun AND huge engine, exhaust, and fuel pump heating.
I am very far from an environmentalist, but the shit that turned the air brown, kept people indoors, and made for pretty sun rises in the Las Angles area, that was HC.
I don't mind people driving big SUV's or starting forrest fires, but for me, the charcoal canister and TWC are always going to stay on my bike because they make a huge difference with little to no negative impacts.
Also note, laws are getting more enforced all the time. I am safety inspection certified in Missouri and have been informed by the officer that inspects my work that Missouri is going to start enforcing the emissions rules on bikes, so if I pass a bike that has the TWC or carbon canister removed, I am liable for up to a 20 grand fine.
Im not over emotional on this. I will happily step aside and let someone else at the dealership pass the bike, but between the risk of getting caught and the knowledge that these things really do matter, I won't pass it myself.
Owned to date. Honda Aero 50, Honda Elite 80, Honda Elite 250x2, Suzuki Katana, Suzuki RF600, Yamaha YZF1000R, Kymco Xciting 500, Suzuki GS500, Suzuki Burgman 650, BMW F800GSx2, BMW S1000RR, Aprilia Scarabeo 200, Aprilia Caponord, Aprilia Sportcity 250
I love and miss you Jeneca and I'm sorry.