Mystery Nipple!

[UI Vandal]

While refreshing the top end of my bike I discovered a mystery nipple. It had no hose attached and was a bit gunked up.

Should a hose from the carb attach ere? Should there be an additional hose attached?
My KIPS area is also missing these two bolts.

What function do they serve?

[JoKDX220r]

The "nipple" is used to plug the case breather hose...
The 2 bolts, if you mean the ones with the number "7" on them are used as stoppers if I remember correctly..

[Tedh98]

The "nipple" is used to plug the case breather hose...

That hose should then go up to and inside the airbox.

[UI Vandal]

The "nipple" is used to plug the case breather hose...

That hose should then go up to and inside the airbox.

Thank you! Guess I'll grab some fuel line hose then.

[Slick_Nick]

The breather hose doesn't go inside the air box, it goes into the little "hoop" on the bottom of the air box by the frame rail.

[Tedh98]

The breather hose doesn't go inside the air box, it goes into the little "hoop" on the bottom of the air box by the frame rail.

Interesting. That wasn't how it was set-up on the '97 and '01 200's I had.

[diymirage]

i've heard of people running that breather hose as well as all the carb vent hoses into the airbox in order to cross deeper waters

on both my bikes this breather hose was run down the engine and tuck in by the rear shock just like the carb hoses

[KDXGarage]

In stock form, there is a hole in the airbox of a few KDX's to place the crankcase breather tube.

[rbates9]

Mine has the breather going up to the air box.

[Slick_Nick]

The breather hose doesn't go inside the air box, it goes into the little "hoop" on the bottom of the air box by the frame rail.

Interesting. That wasn't how it was set-up on the '97 and '01 200's I had.

According to the factory "hose and wire routing diagram" that's where its supposed to go, into that hoop on the bottom of the airbox.

[KDXGarage]

On page 1-22 of the 1997 manual, I am seeing it with an arrow, mentioning "to the airbox".

The hole in the airbox is for the crankcase vent hose.

[Kroynon]

On the 91-94 250s it also goes into the airbox. I had it there until I bailed on a brutal hill climb and the bike was upsidedown on the face of the hill for a while as I climbed back up to retrieve it. By the time I got there most of the case oil had poured out the breather into the air box.
Now I route the hose up the frame and back down under the engine with the carb vents in a loop to avoid this from happening again.

[rbates9]

On page 1-22 of the 1997 manual, I am seeing it with an arrow, mentioning "to the airbox".

The hole in the airbox is for the crankcase vent hose.

My bike was stock when I got it and it went to the air box, and the best I can recall the 95 I had years ago also went to the air box. I can't see why they would have it vent to the ground. If it was in the wide open air then it would suck in crap too much.

[KDXGarage]

On the 91-94 250s it also goes into the airbox. I had it there until I bailed on a brutal hill climb and the bike was upsidedown on the face of the hill for a while as I climbed back up to retrieve it. By the time I got there most of the case oil had poured out the breather into the air box.
Now I route the hose up the frame and back down under the engine with the carb vents in a loop to avoid this from happening again.

Have you considered not looping it out and leaving it upside down as a way "to avoid this from happening again"??

[Kroynon]

On the 91-94 250s it also goes into the airbox. I had it there until I bailed on a brutal hill climb and the bike was upsidedown on the face of the hill for a while as I climbed back up to retrieve it. By the time I got there most of the case oil had poured out the breather into the air box.
Now I route the hose up the frame and back down under the engine with the carb vents in a loop to avoid this from happening again.

Have you considered not looping it out and leaving it upside down as a way "to avoid this from happening again"??

Haha... That would be too easy but may be worth a try.