Hello all, I recently bought an 06 klx250s. So far am loving the crap out of it. I was doing some cleaning and noticed some engine oil around my shock. Searched for the source and found it was coming from one of my airbox drain tubes (the one with the one way valve in it).

I opened my airbox and took out my filter and found there was a large amount of engine oil sitting in the bottom of my airbox. Am I correct in saying that this oil came from the crankcase breather?

Little more looking I found that the bottom of the airbox drain hose was plugged. I unplugged it and immediately I had a big black spot under my bike. Any harm in leaving this unplugged? why was it plugged in the first place?

thanks for all the noob help

 

You might be talking about the overflow catch? I'm guessing...

It's plugged so it doesn't fill up with crap while you're riding. When you notice the little container has fluid in it, you just un-cork it and empty it.

BTW - a big 'black' spot indicates it's time to change the oil...

 

more likely oil from the air filter...

 

rgoers: So I took my "one way valve" off and cleaned it. turns out it is clear! and I believe you are right, it is just a catchment tank. Thanks!

And yes yes I know I need to change the oil the bike was owned by someone who wasn't big on maintenance so it is lagging behind on some things. Next on the list is to change my leaking fork seals though! Might as well change the oil when I have it on the stand!

Thanks

 

Upon further inspection it appears that my airbox has committed suicide. It has a large hole that was melted from being near my exhaust... Time to invest in a new airbox and some heat wrap.

 

I say the little catch unit on the bottom of the airbox hose is plugged so little drips of oil don't dribble onto the ground, resulting in environmental damage (Al Gore approved). I don't worry so much about a little dust getting in from the plug on mine which was lost long ago.

Can you simply use some heat-resistant metal tape to plug the melted airbox hole. I think this repair method has been successfully deployed before.

 

I had the same problem with the exhaust melting the airbox. It had some small holes that I plugged up with silicone and also covered with a small piece of aluminum as a heat sheild.
Dan

 

The drain hose from the airbox is plugged so that dust and dirt don't get sucked into the filtered air stream and into the engine. It has NOTHING to do with pollution or the environment. It's about protecting the engine from premature wear. Just pull the plug from time to time and drain anything that collects there. It's normal for a little oil to build up there from oil vapour breathing up from the crank case, especially on a single cylinder machine, and is nothing to be concerned about.

 

I'm pretty sure the drain tube is on the airbox unfiltered side of my '06. The whole catch bottle is known for ripping off during spirited trail rides and most of us tend to not worry about its absence.

 

Would have to go look to be sure but I believe my 09 is the same way.