Getting the oil fill level just right

[mechanicx]

Anyone else see this with their bike? There is an oil level sight glass. The manual publishes a refill spec with and without filter and completely dry capacity change in liters. On my bike it's something like 3L, 3.2L and 3.4L. I don't normally work on bikes, just my own. For the most part on cars if you add the publish capacity for the most part the level is right where it should be on the dipstick.

But with the bike I always seem to end up filling to some level beyond the top of the sight glass. It's probably not really overfilled by much. Just today I changed the oil without the filter change but I did remove and reinstall the filter so the required refill should've been something slightly more than 3L. I ended up adding a little over 3 QTS but there was still a small bubble of space in the sight glass. I figured when the oil filter fully refilled I would have to add more oil. But I took it out for a ride and when I checked it the sight glass was completely full. Did the oil just expand that much from heat lol? I guess I could test that theory by checking the sight glass now that the oil has cooled.

I doubt it is really overfilled much or matters but it bugs me that level is past the full mark. I'm not sure why I seem to end up slightly overfilled one way or another.

 

[Qwiky]

Your not thinking about it the right way.

You should use the refill amounts as a guide to know if you have enough oil to do the job, that's all.

Just fill until it comes up in the sight glass and your done, simple hey?

 

[ddtmoto]

Yup, your sight glass is your friend, use it for a good fill...

 

[Doog]

On my bikes I always fill with 95% of the required amount. Run the engine and check the fluids hot and top off. My current Triumph holds 6qts and the book says 4qts will drain out. Well, 5qts drain out so I add back 4.8 qts and then run and top off and it always takes 5qts to get it right to full on the stick. But I tilt my bike side to side to drain out as much as possible which the guy who wrote the book probably never changed oil on this model.

 

[eljefino]

On my Virago if I was correct by the sight glass I'd get a red low oil level sensor warning light accellerating up hills. So I went about 2/10 quart over.

 

[mechanicx]

Originally Posted By: Qwiky
Your not thinking about it the right way.

You should use the refill amounts as a guide to know if you have enough oil to do the job, that's all.

Just fill until it comes up in the sight glass and your done, simple hey?


That's the problem I filled it up by the sight glass and somehow I end up filled a little over the sight glass lol. Maybe a bubble somehow got stuck in the sight glass and it was fuller than I thought.

 

[Qwiky]

Unless your fill is not directly into the cranckase and there is some delay in it settling.

If you do it using the sight glass you may end up a little low if the oil filter is dry. I usually fill my oil filters before putting them on so there is less air to purge when the oil pump primes.

Goes without saying the bike has to be on both wheels on flat ground and vertical.

 

[mechanicx]

The oil fill goes directly in the sump for the most part. There is some delay in the oil level settling in the sight glass but the level drops as it setrtles and not increases. The oil filter is mounted horizontally and can't really be prefilled and should've been at least partially unfilled. The bike has a center-stand and is checked in the same position on level concrete. This is why I was kind of surprised that the oil sight wasn't overfilled until after it was ran.

I'm guessing somehow a bubble was in the sight glass and it was already slightly overfilled. It's kind of surprising though because I was sneaking up on the level and the filter needed to be filled. It couldn't be over filled by much. Next time I just won't fill the sight glass so full before running it and sneaking up on the level.

 

[rraiderr]

If I fill the oil filter and put the oil level to the middle of the sight glass after a ride and the bike sits the oil level ends up above the sight glass.

I only fill it up the very bottom of the sight glass so it does not end up overfull after the first ride.

 

[mechanicx]

That sounds like what I need to do. Fill the oil to no higher than the bottom of the site glass and run it for a bit and then check level and top up.

 

[mechanicx]

After some more riding, I notice the Rotella T 15W40 seems to allow for better shifting than the conventional Valvoline motorcycle oil. Not to knock the Valvoline motorcycle oil, but the Rotella seems to work better if anything. The clutch and shifting seem to be better.

 

[Doog]

Originally Posted By: mechanicx
After some more riding, I notice the Rotella T 15W40 seems to allow for better shifting than the conventional Valvoline motorcycle oil. Not to knock the Valvoline motorcycle oil, but the Rotella seems to work better if anything. The clutch and shifting seem to be better.


Quite a few people say that and in all kinds of bikes.