So my bike is a magician of sorts.

I check my oil once-twice every week (every day if I'm riding every day or heavily). I changed it a few months ago and it's been fine until uh-oh, the oil lamp would flick on if I got on the brakes more than gently. I knew what this meant (it has happened before).

I get to my destination about 5 mins away and have a friend help me get the bike level so I can see in the sight glass. 0 oil visible.

Naturally I let it cool so the oil can settle. Come back out a few hours later and still, no oil in the glass. I get home and re-fill it. No light anymore and I've been checking the level.

Like I said, this has happened before. Suddenly a quart of oil is just gone one day. No drips under the bike, no burning smell, no blue smoke. Coolant has a few flakes in it but no oil on the surface (flushing it soon).
About 3000 miles ago I had the valves done and there was a very small leak between the gasket but I wiped it off and it doesn't reappear for more than a week.


I have no idea where I am loosing a quart or more of oil within the span of a few days without it visibly leaking heavily or burning off. And the problem is intermittent. It's not like I'm filling it every day.


My only clue is that gasket leak and I have to do the valves soon so that should be addressed but it still makes little sense to me. Maybe it leaks out more at high revs so I can't smell/see it?

It's a little while before I can scrape the cash together to head over to motoshop to do the valves so any suggestions or ideas in the meantime are appreciated.

http://25.media.tumblr.com/68bf1ac169e6a6797355c60531d6f536/tumblr_muc8ymQFEH1r8q650o1_500.jpg

Check the hole on the left side of cylinder 1. It may be blowing out there like it does on mine. What brand and type of oil are you running I'm curious? I've heard some oils like to burn easier than others...

http://25.media.tumblr.com/68bf1ac169e6a6797355c60531d6f536/tumblr_muc8ymQFEH1r8q650o1_500.jpg

Made me laugh! :thumbup:

Bikes burn a lil oil at high RPMs. It's normal, but a quart I'd be wondering. Have you checked your air filter? Oil might have been blown out the crank and up into the air filter housing.

Check the hole on the left side of cylinder 1. It may be blowing out there like it does on mine. What brand and type of oil are you running I'm curious? I've heard some oils like to burn easier than others...

Rotella T6. If it was simply burning it I feel like it would be more consistent. Like I said, this is a lot of oil gone suddenly every few months tops.

I was going to check the engine and air box today but I have been defeated by an extreme case of vertigo and will check those...idk when my inner ear is non-****ed up. :mad:

Made me laugh! :thumbup:

Bikes burn a lil oil at high RPMs. It's normal, but a quart I'd be wondering. Have you checked your air filter? Oil might have been blown out the crank and up into the air filter housing.

I was going to post this.

My '06 leaks oil out of the airbox after it condenses in there from the PCV gas. Every pregen ninja 250 I've looked at closely does this. You get a leak out of the airbox, and then a lot of nasty looking grime on the bottom of the engine, the front part of the swingarm, and it eventually drips off the kickstand bracket or something, and leaves one little drop of oil on the floor of the garage every other time you park it. Cleaning it off will stop the drips for about 200 miles of short trip riding, and then you get the little drips again.

Is it maybe possible that you have the elusive bike that doesn't leak, but just burns all the oil in there like it's supposed to? I guess that doesn't explain why it's intermittent, but subjectively, my 250 doesn't do this at a perfectly constant rate, either.

You get a leak out of the airbox, and then a lot of nasty looking grime on the bottom of the engine, the front part of the swingarm, and it eventually drips off the kickstand bracket or something, and leaves one little drop of oil on the floor of the garage every other time you park it. Cleaning it off will stop the drips for about 200 miles of short trip riding, and then you get the little drips again.

Have you installed any hose clamps on the pcv hose? I was able to reduce a lot of the leak around the hose by changing the little wire to screw on hose clamps.

Should there be a leak out of the air box? I don't think so... The oil does get in there is supposed to collect in a little hose with a plug that is near the coolant overflow hose on the right side of the bike. You can drain your air box of oil by unplugging the hose and allowing the oil to flow out.

OP, If your bike is burning oil, which it likely is, look at your exhaust pipe for dark discoloration near the tips. It should be especially noticeable if your exhaust is chrome. That would be your sure evidence. Perhaps there is material clogging the leak that is sometimes removed just enough to dump oil into the combustion chamber.

Have you installed any hose clamps on the pcv hose? I was able to reduce a lot of the leak around the hose by changing the little wire to screw on hose clamps.

Should there be a leak out of the air box? I don't think so... The oil does get in there is supposed to collect in a little hose with a plug that is near the coolant overflow hose on the right side of the bike. You can drain your air box of oil by unplugging the hose and allowing the oil to flow out.

OP, If your bike is burning oil, which it likely is, look at your exhaust pipe for dark discoloration near the tips. It should be especially noticeable if your exhaust is chrome. That would be your sure evidence. Perhaps there is material clogging the leak that is sometimes removed just enough to dump oil into the combustion chamber.

I seriously doubt it's designed to leak oil on the floor. The hose has actual clamps on, which I assume were installed by a previous owner. I've tried replacing the hose, but that didn't help, clamps or not.

The real issue, in my mind, is that the airbox is split into two pieces down the center, and the gasket used to seal that seam doesn't appear to be totally impervious to oil.

I seriously doubt it's designed to leak oil on the floor. The hose has actual clamps on, which I assume were installed by a previous owner. I've tried replacing the hose, but that didn't help, clamps or not.

The real issue, in my mind, is that the airbox is split into two pieces down the center, and the gasket used to seal that seam doesn't appear to be totally impervious to oil.

I guess you could call it a design flaw. The oil is vaporized and the wire clamp that is on it does not contain all the vapor molecules. Some molecules escape through the end of the hose and collect, and without any cleaning over time collects enough to drip on the floor. The hose clamps are an improvement and allows the hose to retain more oil.

I know my bike burns an small amount of oil, but there is no leak from the air box. It does collect in the hose though. Perhaps the gasket in the air box needs to be replaced or cleaned. There is a lot of work involved to remove the box to do that though.