Forum

[Thack]

Papasmurf writes: "It is significant on my BMW K75S. About an 1/8th of an inch on the sight glass."



I think 1/8th inch is pretty small. But most particularly it's small in the world of the UCE which, as we know, varies by more than the whole windows height.



If the difference between freezing cold and extremely hot oil is just 1/8th of an inch on the sight glass, then that would be too small for me to worry about. But that's just me!

[Thack]

Damn! Can't edit..... I meant "the whole height of the window".

[papasmurf]

Thack when setting out on a 600 mile trip with an engine that has done 95000 miles, an 1/8th of an inch is a lot.

[Thack]

Sorry, mate, not convinced!

[jefrs]

I have a C5 Efi and see much the same thing in the sight glass - a random level of oil each time. Considering that it's not leaking and burns very little oil I expect it to remain constant. I'm coming to the conclusion that much depends on the angle the bike is sitting on its stand, and that if any oil is seen in the sight glass then it's ok. When I stuck 100ml in, it went over the full mark and had to be dredged out (messy). If I open the filler and stick a finger in, it gets oil on it: there's oil in there. It is far better for the engine for the oil to be a little low than overfilled.

[papasmurf]

A motorcycle needs to be spirit level level to check a sight glass.

[Deanobats]

More on the pesky oil level saga. I know my Bullet was over-filled, but only just, I could see the top of the oil in the sight glass when I just gently rocked the bike back and forth. I thought a few extra ml won't make much of a difference. Anyway, it started to bug me, so I warmed up the bike, switched it off and let it sit for ten minutes and then loosened the bolts on the oil filter on the bottom of the crankcase just enough to let a little drip out into a container. I watched, and waited and very very gradually the level on the sight glass appeared and then slowly went down to about half way between the max and min marks. I then tightened everything up, started her up, rode around the drive a bit, sat her on the centre-stand and looked again, half way up fine. I had pulled out about 200 ml of oil in the meantime, not exactly a small amount.

Anyway, off I go for a spin, about five miles, come back, up on centre stand and the bloody thing is over the max mark again! So another 100 ml comes out to bring it back down again. How the hell are you ever supposed to get a decent oil level in these things?

[Deanobats]

Update. Having finally got it to half-way between the max and min marks on a level drive, I wheeled it, WHEELED IT mind, into the garage. Guess where the oil level is now? Over the top of the sight glass. Sigh.

[Smudger]

I know mate, mine is exactly the same, it's doing my nut in!!!
I've decided not to check it anymore.
I recently changed the oil and there is a little over 2 litres in there that I know of, so I'm gonna leave it at that!!!
It reads over and under without even starting the thing up!! Who knows????

Dave

[Les]

Now for my take on this, I have observer on my EFI that the oil level in the sight glass is lower when the engine is hot I presume this is because oil is laying in all the nooks and crannies but drains back as the engine cools especially if you move the bike about, so I set the oil level in the glass when hot as per the book instructions, if you set it when cold you will not see any oil in the glass when hot so makes it difficult to make a quick check of oil level when say out on a ride, setting it as per the book will mean the level will appear high when cold, this does not seem to cause any problems the amount of oil between the top and bottom of the glass is very small anyway, when oil levels are checked hot there is always a chance of slight variations