Air Box Mod


Hey, has anyone ever had oil leak after doing the small air box mod on a GEN 1? Also, is the middle hose on the airbox supposed to stay hooked up?
FILT166...I forgot to hook the crankcase breather hose back up. It's the middle hose coming from the Air Box down to the engine. RSD, you are correct
Both sir. I have my bike tuned for the small box mod and have an extra box for my bike.

If you are already tuned for it...the rest is easy. Flip yer air box over,remomove the componant from the middle,use a simple twist action.Now reach in and pull out that plastic flapper valve.Doesn't matter if you destroy it getting it out,it is no longer needed. Now plug the hole.I used a peice of plastic cut to fit. I used the lid from a rattle can,the more flexible type,less brittle,easier to cut. Then put hi-temp silicone around the diameter of the hole,stick in plug,let dry. Dont forget to plug the rubber hose that once led to the componant(the flapper actuater).

Small Box Mod Done.

#1 busa your so rude.... Hana Jk... I know about the search but I was being lazy
Thanks rsd

"Search" doesn't always provide the gold. I usually get bored sifting thru dozens of posts.

Took me less than a minute to type out yer answer. most questions dont get answered that fast,if at all, with the search.:thumbsup:

if you want a true small airbox mod, you also cut out the floor of the airbox under the air filter, all the way to the lip that the air filter rests on.
I will look into this mod and do it as I have another air box to cut out.
Now lets say with this mod, what do you loose n gain?
Any real input on this?
Are we loosing torque but gaining HP? How much of each n just an estimate.
Thanks guys
The jury is still out.
I have seen die hard land speed guys say that it hurt them.
I did some testing years ago and it showed a gain.
I can't remember the exact numbers, so i'll addlib.......
First pass was from second gear at 60mph, going thru the gears between 2 signs{on a closed course, ofcourse;)}. The signs were about 9/10ths of a mile apart.
I went 182mph on the GPS.
Went back in 6th gear at about 100mph and rolled the throttle for the same distance.
Went I think 183mph.
Went home, did the small box mod and went back 2 hours later. Did the same 2 passes, and went 3mph faster on both.
The bike was a stock 2000 model with Yosh bolt on mufflers only.