Oil Pan is Emptying Itself

[skate13420]

Thanks to everyone for responding, i replaced the petcock and took my carbs back to the shop that did the work on them, they checked them out and said that they were set fine. I figured out my compression problem, my clutch was slightly engaged and when i looseded the tension at the handlebars, i regained compression. I have a new problem though. About a week ago i changed my oil and refilled it according to the specifications in my manual like i always do. The bike sat for about a week and yesterday i went out to start it up, and my oil pan was dry! I could see all the way to the bottom of the pan! There was no puddle under the bike, and when i drained it a week ago, i got slightly less oil out than i put in. Where is my oil going, and how do i fix this problem?

Thanks ,
Jasson

[skate13420]

The bike is a 1981 Yamaha xs400H Special 2

[Gummiente]

Where is my oil going

Well, somewhere it isn't supposed to. My guess is a seal has let loose inside the motor somehwere and allowed the oil to drain into an area it's not supposed to be in. But I can't remember if your bike is a wet or dry sump (ie: if the oil pan is directly under the engine it is a wet sump); and whether or not the engine oil also lubricates the gearbox. So if the gearbox on yours has its own oil that's separate from the engine oil, that's where I'd check first to see if there's any engine oil mixed in with it.

[TechTMW]

It's a wet sump motorcycle ... and it's a pretty small case, but the transmission shares the case ... there's no where for the oil to go.

I still think it's oil gnomes ...

Did you store the bike on its centerstand or kickstand ... and how did you see the oil pan - through the fill hole or the sight glass?

[skate13420]

the engine and the gearbox share the same oil, i'm not sure if there is a seperate fill hole for the gearbox, but i'm pretty sure that there isn't. I saw that the pan was empty when i took off the filler cap and looked inside. I could also stick my finger all the way down inside and not hit the oil. I stored the bike on its centerstand.

[TechTMW]

Are you sure that's not just a baffle that your finger touched, and no the bottom of the oil pan? Does the bike have a sight glass?

There's nowhere for the oil to go - it's either
1 still in the bike (In the sump where it's supposed to be)
2 stolen from the bike
3 still in bottles on the shelf because you forgot to refill (Hey I've done much dumber things!!!)

Don't mean to sound like an "O Ring", but there really isn't anywhere else for the oil to go if the bike just sat statically.

[skate13420]

it does have a sight glass, but it's as good as useless. Also, i forgot to mention that the oil wraning light did come on, and i'm positive that i filled it up

[niterider]

I know that is an old topic, however; I would like to know, where did the oil go?

[kar_the_terrible]

Yup I have the same problem with my bike. Oil seems to go away, without puddles. I know that my gaskets and seals need replacing soon. I intend to do that when the season ends and my bike is in storage.

I would take a look below the engine. The oil (assuming 20W40) has a tendency to clump and sit below the engine, with all the dust in it, the goo refuses to "drip".

My bike runs just fine, I top off the oil every two weeks. Relatively certain that a new gasket set will make the situation better.