Oil drain from frame

[Jeremiah]

I know that there are a thousand threads on TT about oil, oil changes, standard oil filters, stainless steel oil filters, blah blah blah. However, I didn't see anything about my question during my search.

I changed my oil tonight and I drained it out the bottom first, rather than the frame. It seemed like a lot of oil drained out the bottom, but I didn't pay that much attention as to how much drained. When I pulled the plug on the frame no oil came out. I was a bit surprised, because I've drained the oil in that order before, but I've never not had oil come out of the frame. During my last ride, my oil level appeared to be just fine...not low at all.

I'm just trying understand why no oil came out of the frame. It's not like I let it sit and drain out the bottom for an hour. It only drained for about 5 minutes. Any thoughts?

Thanks,

Jeremiah

[YZ250F_Rider]

the bottom what?/ The bottom bolt in the crankcase or the bottom bolt that holds the oil feed line onto the crankcase?

If you drained the oil without first starting the biuke and it's been a day or more since running it, all the oil had already drained into the crankcase and none was left in the frame.

[Jeremiah]

The bottom bolt in the crankcase. I was wondering if the oil had just drained from the frame, but it hadn't happened like that in the past. I was under the impression that 1.7 quarts was enough to reside in the frame permenantly...not fill it...but at least pool there some.

[grayracer513]

No, all of it will eventually run down hill. There is a check valve in the right engine cover that closes when the engine stops which is intended to slow the process down, but the oil ends up leaking by the oil pump drive shafts, and given enough time, none will remain in the frame.

That's why you can't check your oil until after you start the bike for a minute or two.

[Jeremiah]

Thanks for the info. I can always count on TTers.