Where does the oil go?

[Charliedog]

This might be a silly question,  but I can't help but be curious.  I changed the oil in my 2000 C10 about a month ago, replaced the filter, and added 3 QT 6 oz.  Ran it and checked for leaks, let it sit about 5 minutes, and checked the level in the sight glass-it was just above the full mark.  I haven't ridden it since, but when I checked the oil level today, the sight glass was almost empty.  Just a hint of oil at the bottom.  Still no sign of visible leaks, no sign of smoke at start up even tho the bike just turned 100k on my way home from AIMExpo.
So, did the oil 'shrink' with the cooler temps?  Where did the oil go?

Larry  aka  CharlieDog
Bristol, TN 

[DC Concours]

That is an interesting puzzle. But one thing is for sure don't be riding it like that. Or else next time you'll be asking why doesn't the engine go.

[Ron Dawg]

Pretty normal. My 2000 did the same thing. If you're sure you drained the oil from BOTH plugs and put in what you said, it should be okay. Run it and check if on the center stand 15 minutes after you stop then a week later. No idea where the oil goes, but it doesn't "go away". It drains down somewhere. You're liable to get more problems by letting it sit for a month unless you put Stabil in the gas and run it long enough to get it in the carbs. These bikes clog on the ethanol/gas mix you get today and it only takes a couple of weeks.

[T Cro ®]

It's still there... It's just hiding! Consider this the engine is basically divided into two compartments one being the engine and the other being the transmission so there are walls that serve as dams and valleys that can trap oil as it drains down from one location or another... When you start the engine it is then redistributed throughout the engine and you will see the sightglass return to normal....

[Charliedog]

Thanks, Tony.  That's what I thought might be the case. 

[DC Concours]

What are you guys speaking of? I have never had my oil hide. If you put your bike on the center stand shouldn't you see the sight glass fill up? I do. Always.

If the oil was hiding how would you be sure you were draining it all?

[T Cro ®]

What are you guys speaking of? I have never had my oil hide. If you put your bike on the center stand shouldn't you see the sight glass fill up? I do. Always.

If the oil was hiding how would you be sure you were draining it all?

And exactly how long have you owned a Concours and not noticed this? I can't tell you how many times I've read threads here just like this one in the 15 years I've been hanging out here....

[DC Concours]

Couple of years and every time  I check. About 10 times thus  far. Do I have a special bike that doesn't hide oil?

[Charliedog]

While I put about 10k miles on my C10 yearly, it is not my everyday rider.  It may sit a week or two, or three, between rides.  I rode the bike yesterday and just checked, the oil level is just over half way up the sight glass.  But three weeks from now, the window will be empty.  With no visible external leaks.  Just the way it is.

Larry  aka  Charliedog
Bristol, TN 

[T Cro ®]

Couple of years and every time  I check. About 10 times thus  far. Do I have a special bike that doesn't hide oil?

Very likely that you have simply never looked in the same particular order that the OP has as well as many others that have seen the disappearing oil... The best of my memory serves it up something like this. Owner checked or changed the oil with bike on CS and then let the bike sit overnight or longer and on checking the sight-glass again and did not see the oil... Freaking out they add oil to the engine without starting and then re-checking; they then end up with an overfull bike that covers the sight-glass to which starts another thread saying that the sight-glass is a worthless POS....

[VirginiaJim]

And exactly how long have you owned a Concours and not noticed this? I can't tell you how many times I've read threads here just like this one in the 15 years I've been hanging out here....

Is that in dog years?  15 years eh?  It will be 10 for me this coming summer.   My how time flies..

[T Cro ®]

Is that in dog years?  15 years eh?  It will be 10 for me this coming summer.   My how time flies..

Woof (bite me) Woof...   

[VirginiaJim]