My bike is thirsty. It's drinking oil! and there's that water in the airbox thing.
 

I checked the oil level today and it was almost empty.
Last time that I checked the oil level was about 3 weeks ago and it was almost full.
I did work the bike rather hard in the last couple of days. I rode more than 800 Km in three days, including a nice day offroad and high speed motorway riding.
Anyone else encountered this?
I was told that big bore singles use oil, but this seems too much. Especially when considering the fact that the bike is on the road for less than a year.

On a different subject:
After a water-crossing that I did, I drained the airbox oil tube (it was full all the way up). To my surprise, after the oil water came out.
Today I removed the air filter and looked inside the airbox. There was some residual water on the left side of the box.
I reckon that most of the water that got in the box, went into the lowest part of it (i.e the connection to the drain pipe, which is rather deep).
The bike runs as usual. No new sounds or behaviors.
So my questions are:
1) What are the chances that I caused major damage?
2) How can I tell if there's water in the system?

Sounds like somethings a miss to me.

I did a 500km+ day on my Ten, nearly all of it on the motorway sitting at between 65mph and 80 and it didn't used any oil really, Little in the airbox drain but nothing to need draining out.. That was on a loaded bike too. My bike has 9000 miles on it and doesn't use any oil between services.

If water has got in the engine and mixed with the oil it will have made the oil go white and creamy, As for the oil use :017:

See from your ride reports its very dry and dusty there, when looking in the airbox was there signs of dirt and dust on the intake side of the filter?

What is the mileage of the bike?

Should I be able to see the white color of the oil on the dipstick?
I just added oil, so I'll check it tomorrow morning.

The current filter is brand new (just installed the DNA filter).
When I removed it today, There were some dusty patches on it. But nothing serious.
The bike is almost at 18,000 Km.

Probably a good idea to replace the oil & filter with some good quality semi synthetic and keep an eye on the level.

Water getting into the filter and possibly the engine (in small amounts) will just get thrown out through the zorst valves etc, so you might seem some steam in the exhaust outlet for a short while along with a bit of a cough... I'd suggest you clean the filter, oil it and clean out the airbox and drain pipe too if you're worried.

If it's running OK now and the plug looks like it should, you've probably got away with it. Too much water in and she'd of died or hydraulic locked on you and you'd have known about that..

The most I did in one day was 800km and I had no oil consumption(this was after the replacement of the breather by the modified one). The speed varied from 110kmh to 130kmh(so between 4000 and 5000rpm). How do you check your oil? Ya know it's a special procedure with a thumper with seperate oiltank(=frame): warm it up, let it idle for a moment, hold it upright and check it with the dipstick not screwed in.
For the water, yeah well....
Greetz, Hans.

Note: I run an oiltemperature gauge, always warm the bike up to say 80C(while ridin') before revving it.

I check my oil level after a short ride, otherwise it will show different levels.

I only know of one XT660 that was using excessive oil, dirt got past the air filter & wore the rings, piston & cylinder out. The cylinder was rebored to 102mm 686cc & replated, new piston & rings were fitted.

I usually check the oil at the end of my ride back home from work.
It's a 12 Km ride and it usually takes me about 20 minutes (I don't rev the engine on that ride).
I still have the 08 breather (our dealer is reluctant to change it under warranty). The airbox oil tube is usually full after 2 weeks or so. But that's such a small amount of oil, so it couldn't explain the oil disappearance.

I guess that I'll have to take the bike to the shop. It's time to change the rear brake pads any way.

It doesnt matter what your dealer thinks it is done under warranty and authorised by Yamaha. email Yamaha like I did and they will instruct them to replace it for free. Any problems let Yamaha know and they will sort it out directly with the dealer.

Check it all thru again tomorrow...