What are the holes on the side of the air box for on the KX500?

[JohnJr]

Hello guys I have an 01 K-5,what are these holes on each of the boxes used for and do you supposed to kept them open or one of them closed or what ,can somebody help me,thank-you,John

[martinfan30]

Seems to be for riding in areas with lots of water. If you lay it down, the box wont fill with water as quickly. I leave mine closed. There seems to be enough open area under the seat for incoming air.

[Johnniespeed]

I leave mine closed too, engine revs up fully with full power, so I leave them shut.
 John

[KX500freak]

as for i think and experienced,the holes closed is way less dirt on the filter.
but it can hold water out to..
but for sumo i even removed 1/4 of  the airbox to allow more air in.

[JohnJr]

Hey thanks for that quick info, after I got it home I noticed that they were open,have to buy a book.Peace my friends,JohnJr

[grywache]

I wondered the same thing and noticed when I had a larger main jet if the air box doors were closed it would not run good, only if they were both fully open would the bike run properly. then I changed it to a smaller main jet due to the new elevation that I am at and the bike runs perfect with them both open, but I haven't tried it with them closed yet. I was just searching on the internet and found a little info about testing your jetting with the air box opening.

http://www.thumpertalk.com/forum/archive/index.php/t-789167.html
"
The original main jet is too large (rich at WOT): Testing with the airbox door off will lean the air/fuel mixture closer to ideal and the bike will run better than with the airbox door on. Reduce main jet size and retest.

The original main jet is too small (lean at WOT): Testing with the airbox door off will lean the air/fuel mixture even more and the bike will run worse than with the airbox door on. Testing with the airbox opening restricted will richen air/fuel mixture closure to ideal and the bike will run better than non-restricted. Increase main jet size and retest.

The original main jet is just right (ideal air/fuel mix at WOT): Testing with the airbox door off will lean the air/fuel mixture from ideal and the bike will run worse than with the airbox door on. Testing with the airbox opening restricted will richen the air/fuel mixture from ideal and the bike will run worse than non-restricted. Main jet size is correct. Now go find the ideal jet needle position and read the sticky on confirming your pilot circuit. "

So by the sounds of it the holes on the side of the air box allow you to adjust the air/fuel mixture slightly.

[kawi4ever]

I also use the air box holes for slightly leaning the airfuel mixture, if its nice outside i usually leave them open but if its wet and muddy i keep them closed. Don't notice any seat of the pants difference open or closed but you could tell your friends it adds 10 to 20 HP and its a KX500 secret..LMAO   

[Motorrad]

I also use the air box holes for slightly leaning the airfuel mixture, if its nice outside i usually leave them open but if its wet and muddy i keep them closed. Don't notice any seat of the pants difference open or closed but you could tell your friends it adds 10 to 20 HP and its a KX500 secret..LMAO   

you must have trick aftermarket billett ones, my stockers only add 5hp.

[Friar-Tuck]

KX 500 E12 (2000)
Owners Manual Page 10.
   Air Cleaner Rotary Shutter
A rotary shutter is equipped to the left and right side sides of the air cleaner case respectively.
  When the shutter is opened, extra air is led to the air cleaner case,so more efficient intake is obtained.
    NOTE
The rotary shutter should be closed in wet conditions to prevent rain from entering.


 Tuck\o/

[Polar-Bus]

I always thought that door was to let the mice in and out during winter storage. 

[Roostmad1]

I leave mine closed too, engine revs up fully with full power, so I leave them shut.
 John

i in the manual it says the vents can be opened for additional air=more HP

[Johnniespeed]

 I will open mine right away, I want that 10 to 20 HP, I bet fuel mileage will increase and it will decrease arm pump.  I wish I would have thought of this sooner.
  I have about a hundred decals and stickers on the shelf. Do stickers increase power ? I know that my green jersey is faster than my red jersey.
  I know that fart cans make the ricers go fast, and cold air intakes do not just make noise and cause throttle icing in winter, they do add power, the advertisements show dyno results.
  One of the true joys of owning an old school, old technology KX500 is blasting past a group of arrogant 450 owners, who think thier "new" four stroke technology is so superior. And then watch them, in their own disbelief try to make excuses why that antique 500 passed them.
John

[ToomanyKaws]

Its hard for many with 450s to remain friends when you ride a 500.   Especially when they run out of excuses.

[Polar-Bus]

The only thing those adjustable airbox windows let in is MORE MUD AND WATER !

Those things were dubbed as "usless" back in '88 when they first appeared on all the KX bikes, just leave em' shut....