Where'd the extra oil come from?

[Arkmage]

I finally got the GS to fire up, idle smooth, and drive (only for 2 miles as it's leaking oil on the header pretty badly).

After warming it up I turned the bike off, put it back on the center stand, and did my last minute checks. Checked the fork air pressure, checked the tires, checked the oil, etc. The oil was near the bottom of the sight glass, which wasn't surprising since I tipped the bike onto the kick stand with the stator cover off yesterday. I added oil and brought it back up to full.

No problem right? Well, after I put on all my gear for a 2 mile ride, took it around the block, and parked the bike again, I put it up on the center stand. As I was checking to see how bad the oil leak was I noticed that the oil is now OVERFILLED! WTF? I've never had a leaking engine randomly increase it's oil level, especially right after being shut off (usually low until everything drains back down).

Did I do something wrong? Can someone fill me in on where the extra oil came from (or rather where it was hiding when I added more)?

[bwringer]

Oil expands when it gets hot, just like everything else.

[Rkt-Rch]

Did you fill it when it was on the center stand ? Correct me if I'm wrong but I read that it needs to be OFF the center stand on both wheels on flat level pavement! When it's on the center stand on mine 85 GS700ES it looks empty, when I take it off and try to balance it and look at it at the same time (Real Pain unless you have someone to help LOL) it is at spec.
Oil breather/Gaskets/oil cooler/ just to mention a few... I got lucky the other day after leaving the Drag Strip with a pretty good oil leak and found one of the Cap Nuts on the left outside right below the valve loose... Thought I blew my bike up at first!! But all is well now.

[Arkmage]

I think this is beyond heat expansion... it is above the sight glass, that's a heck of a lot of expansion.


I've always been told that if the bike came stock with a center stand the oil level should be checked on the center stand. Maybe someone can fill us both in on this one.

[Rkt-Rch]

If you go to bassclif website and download or find the manual for it I believe it tells you. Again this could have been one of those Marley nights.

[LarryA_Texas]

gas?

I've always thought you checked the oil on the center stand. Went to Basscliff's web site and looked at the OM for my bike and it doesn't say...hmmm


anyway....TWO possibilities:

When you are filling the oil it takes a while for it to get down to the sight glass. Not knowing how quickly you filled the oil I'd guess you just put too much in there.

Or...maybe you left the petcock in prime and allowed gas to flow into the carbs, through the engine, and fill the crankcase. It mixed with the oil in there and will overfill the oil. If that's a possibility change the oil now.

[Arkmage]

I've always thought you checked the oil on the center stand. Went to Basscliff's web site and looked at the OM for my bike and it doesn't say...hmmm


anyway....TWO possibilities:

When you are filling the oil it takes a while for it to get down to the sight glass. Not knowing how quickly you filled the oil I'd guess you just put too much in there.

Or...maybe you left the petcock in prime and allowed gas to flow into the carbs, through the engine, and fill the crankcase. It mixed with the oil in there and will overfill the oil. If that's a possibility change the oil now.

Petcock is brand new and I made sure to turn if off prime as soon as I confirmed fuel in all 4 bowls. So, I'm leaning towards I'm an idiot and just filled it too quickly. I guess I'll drain the extra out (and see if it smells like gas just in case) and see what happens next time I need to top it off.

[mighty13d]

I've always thought you checked the oil on the center stand. Went to Basscliff's web site and looked at the OM for my bike and it doesn't say...hmmm


anyway....TWO possibilities:

When you are filling the oil it takes a while for it to get down to the sight glass. Not knowing how quickly you filled the oil I'd guess you just put too much in there.

Or...maybe you left the petcock in prime and allowed gas to flow into the carbs, through the engine, and fill the crankcase. It mixed with the oil in there and will overfill the oil. If that's a possibility change the oil now.

It's pretty straight drop for the oil down to the sight glass so I doubt that's a possibility. Also, he said he was running the bike down the street. Gas isn't going to fill the case while it's running. And there's little to no possibility of it spontaneously filling the case in the time it takes for him to stop riding, park it and flip it onto the center stand.

Edited: I stand corrected. I re-read the owner's manual and it does indeed say to first place it on the center stand, drain the oil then replace. This is the factory manual btw. I know I read somewhere that it's supposed to be on both tires, but until I see it again, I guess I'll keep it on the center stand!

[DanTheMan]

My Haynes manual says to check oil level on the center stand. I assumed it got this from the owner's manual (I do have the PDF copy of that as well, haven't referenced it). Of course, on the centerstand you need to be on a level surface and it must be sitting naturally on it, i.e., not weighted down by luggage in packs or trunks. It's always worked for me.

[fenderfreek]

If you filled it up cold and then checked it hot, it's not unreasonable to think that it would go a bit above the glass. The oil circulates a bit and goes lower in the glass when it's running too - did you add oil while it was on?

If you do overfill, you can use a little siphon pump though the filler hole to suck it out. I had to do that once when I added too much and found the same thing.

In the future, add a little under the service manual spec. capacity, run it on the centerstand, then turn it off and see what the level looks like.

[Steve]

Also, depending on how long you "warmed it up", some of the oil just hadn't had a chance to drain back down to the sump yet. The bike will run quite well, even though it's not up to full operating temperature, and the oil in that cooler motor will take its time getting back to the sump. If you checked it in that condition and filled to the line, yes it could be over-filled. How long after you shut it down the second time did you check the sight glass?

Also, for those that have manual in front of them for reference, we have now established that the bike should be on the centerstand. Does it say anything about checking the oil level when cold vs. hot? Just for consistancy, just like the tires, I tend to check the oil when the bike is cold. That is the only time you can somewhat guarantee any semblance of consistancy.

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[Arkmage]

Also, depending on how long you "warmed it up", some of the oil just hadn't had a chance to drain back down to the sump yet. The bike will run quite well, even though it's not up to full operating temperature, and the oil in that cooler motor will take its time getting back to the sump. If you checked it in that condition and filled to the line, yes it could be over-filled. How long after you shut it down the second time did you check the sight glass?
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I couldn't say for sure but I'd say at least 10 minutes. That's usually plenty on one of our cars, but with an air cooled motor and this thick 10W-40 it may have needed more time.