What's going on everyone, I'm new to the dual sport riding scene and I just picked up a 2007 KLX250S with 2900 miles on it. I have put a little over 100 miles on her now and I am loving every minute of it, but I've got a few questions that I could use some help with. I've noticed that after a long ride and the bike has been running at temp for a while it starts to have a small oil leak. I thought it was coming from the drain plug but after taking off the skid plate and the front sprocket cover and cleaning all the chain grime and oil off I found that the leak was not coming from the drain plug and that it was coming from (i may be calling it the wrong thing but will post pictures) where the crank case meets the bottom end which is usually hidden by the front sprocket cover. If you look at the pictures the leak is coming from where the copper color meets the silver color right above the bottom qtip lol. I am not sure what weight oil the previous owner used but if I used a heavier weight oil could that help the leak or could this be a gasket issue? And only leaks when hot. Thanks for any info as I am new to this and could use some help.

 

Look real close, which I really can't do in pictures, make sure it's not just some chain lube that will get a bit less viscous with higher temp from the engine. That is pretty much exactly where it would get slung from the chain.

 

Ok I'll take that sprocket cover off again clean that grime some more and let it warm up and watch it. If you look in the 3rd picture where the curved area is above where the bolt threads in, I would wipe it clean and it would puddle up and drip down the side over and over. Also what does everyone use to clean that chain grime and oil off? Thanks for the reply and I will go take another close look at it.

 

Well I just took that sprocket cover off again and looked closer and I some how missed this. I have a crack in the case that is leaking to oil. If you look in the picture below, beside the bolt housing for the sprocket cover there is a crack.

 

It looks like there's been some chain rub on the case, that I would think could cause a stress fracture.
How much oil do you lose?
It might be a good idea to remove the side cover and inspect it (maybe repair it) and then re-install it with a torque wrench...just so you know what's what.

 

Those were my thoughts as well on the crack.
It only leaks when the bike is running and it doesn't pour out but is steadying coming out.
How hard is that to do? And when you say repair it how would I go about doing that?
This is my first bike which I just got a few days ago and I am not the most mechanically inclined but can do basic oil changes and brakes and am wanting to learn how to wrench on my bike. Thanks for the info and help much appreciated!

 

If it were me...I'd remove the side cover and clean it many times and then use some sort of JB Weld type of substance on the inside that can take contact with petroleum products, making sure not to block any moving parts, and then lay it on thicker on the outside of the case. Let it cure longer than required (just to be sure).
You'll want a torque wrench to put the cover back on so you don't crack it somewhere else.
Others might have better advice.
If it's not bad, just annoying, then I'd lean towards not fixing it, but keeping a close eye on it...and wait for a parted motor to get a used side cover.

 

No need to clean it many times. Do it well once.

 

I'd say its more towards the annoying side than it is bad, so I am going to keep a close watch on it for now and keep an eye for a used side case. If starts to leak more will try and take off and repair my self.
Any ideas as to what could have cased the chain to do that? Just a loose chain?
Thanks for the help MaximusPrime

 

What Max said, looks like chain came into contact with case... Have you adjusted chain at all? Make sure it's within limits...