Removing the airbox and adding pods filters requires re-jetting (an increase of main jet size) of the carbs and possible exhaust changes as well. All this combined may result in a 3-4 HP gain (at the top end of the rpm range) which also comes with a loss of mpg.
Removing the airbox makes carb maintenance easier, but can make for more frequent and constant tuning issues if not done correctly.
Removing the airbox is not as as simple as it sounds and will require patience, trial and error to get the tuning right.
It is possible to get similar results, if not the same, keeping the airbox and adding a slip on exhaust pipe and adjusting the needles and idle mixture screws.
I am turning my ninjette into a bobber. I removed the air box and added pod filter my bike runs better even though I still have to re-jet. I also will be redesigning the factory exhaust to baffled straight pipe. The bigger issue is that no my bike is so loud that people cover their ears when I drive by. The noise is a huge problem for me as well because it makes my ears ring not to mention I will be pulled over. What is the solution to bring noise level into a legal range? I've considered installing 12" baffles between the carb and filter. Any ideas or successful solutions would be helpful. Thanks in advance!
Cons: Loud, can be annoying, and rejetting. In addition, time consuming and not worth the time for me. If you are trying to squeeze out as much power as you can and you already have a full exhaust, then go for it.
Just do: Kleen air delete, remove snorkel, and get a slip and you should be OK without rejecting. Some slips does not require you to rejet. But if you already bought a jet kit go full exhaust.On the dyno I got 34hp out of my AreaP full w/ rejet, and pods before I sold my setup. My 250 is more of a street bike now, so I'm happy with just a slipon. I spent a lot of time and money on doing all that, plus having it tuned. Be prepared to do the same if you get pods, exhaust, and so forth. If you are not planning to track the bike, save the money for a 600.
I would highly recommend that you DO NOT REMOVE THE AIR BOX, the carburetors on the bike are CV type and need to box to function properly, buy a K&N that fits the OEM airbox(K&N KA-2508 Kawasaki High Performance Replacement Air Filter by K&N* *Amazon.com: K&N KA-2508 Kawasaki High Performance Replacement Air Filter: Automotive* ) that's the short version.
Long boring but important answer, CV carbs stands for "constant velocity". The function of the carbs is dependent on having a calm reservoir (airbox) from which to intake air at said constant velocity. Pods draw from the turbulent, unpredictable air swirling past them as you ride, which is anything but constant. Other carbs work fine with pods. CV's = no bueno, save yourself the headaches.
Now onto jetting, first you need to tune the idle mixture screws first, I recommend 3 full turns out from bottom as a good starting point, then fine tune them afterwards. As far as buying a jet kit, I personally don't have one on either my 250, or 500 ninjas. I did got up one size on my main jets, due to they are lean from the factory, and shimmed the main needles with a small washer.
i bought a 98 with pods that wouldnt stay on according to the previous owner, so i ordered a airbox off ebay fought and struggled to get airbox mounted, the spent a week trying to get the boots on the carbs, damn glad i never became a motorcycle mechanic!!!! i pulled the box back out, figured out why the pods wouldnt stay on, figured out why the clutch wouldnt engage, figured out why it wouldnt start without using starting fluid, cleaned carbs 20 times, runs effin great!! a little 250 hauling a 240lb man, it outruns my xl 350 and my buddies whatever 450 hotrod, i got some miles on new plugs when i get about 100 miles on the plugs i'll pull them and check them see if im running lean, rich or inbetween, anybody wanna buy a factory airbox for a 98?
When ever you allow more air in or out you most definitely should allow more fuel in by rejetting It's not that hard don't be lazy. lean bike can run hot and burn valves . these things come lean from the factory as it is. So, if your gonna do it, do it right, or don't do it.:|:|