Hitchcocks Forum

I've had my 2013/5000miles B5 for a couple of weeks now and have been riding it when the weather is good. When I picked it up, the dealer had done an oil/filter change as I'd asked. The day after I got it home, I checked the oil level using the method in the book and as advised on here. The oil was above the top mark, indeed above the window itself after warming up, stopping and leaving for 2 to 3 mins. When stone cold you could just about see the top of the oil in the window. I assumed the dealer had put too much in and so I took out approx 200ml of oil to get it correctly on the upper mark. I've done about 100 miles since. Checking it today, using the method above, the oil level had dropped below the window. Leaving it to get cold, you could just see the top of the oil in the very bottom of the window. So, I topped it up with 120ml to get the correct level again. The bike does not leak oil and there's no indication at all of it burning oil, so I can't work out what is happening here: does the oil take ages to get back to correct level on these engines, or is there somewhere where it gets trapped somehow if you have been using the side stand after stopping? I did use the centre stand stand for the proper level test BTW. - Any ideas anybody?

The bottom of the crankcases are compartmentalised to a small degree so the engine does need to run in order for the oil to be distributed so that a repeatable result can be obtained. Hence the advice of putting the bike on the centre stand and running it for a few minutes and then waiting for a few minutes to allow the oil to settle before checking the oil level.

I have found on my classic EFI the level in the sight glass can vary a bit, as you have found the amount of oil needed to make a difference in the level in the glass is quite small, so as long as it is not below the bottom or over the top it should be ok what you add or remove is very small compared to the total amount in the engine, many different ideas and opinions on this subject, the sight glass set up on this engine is just not as precise as most other types of bike, yours sounds ok to me no need to be concerned over it

PB1, this question keeps coming up and the general consensus seems to be that the sight glass is pretty inaccurate. The bottom of the engine is so compartmentalised that oil hides in all the holes and corners.
As long as you can see something in the sight glass you'll be fine.

Okay thanks Gents, thanks for the info. I'll stop worrying to much about it. There was no oil mist getting into the air filter housing so it probably wasn't overfilled initially. I'll keep an eye on it though.

Hi, I check my oil level with the engine idling and warm, never failed me yet

I agree with PeteF; there is little to be gained by obsessing about what the sight glass indicates. As long as oil is visible you're good to go. Having had similar issues with BMW of lheads in the past I use the same technique I did for those: when doing an oil change I drain out as much oil as I can, tilting the bike every which way and then add a measured 2.3 litres as specified in the w/shop manual. I do this by adding 2.1 litres via the filler and 0.2 litres through the filler at the top of the primary chain compartment. I believe that this is why I don't apparently overfill the crankcase, as evidenced by the sight glass. My C5 has never breathed any oil mist into the air box (it wouldn't matter much if it did as I have a carb fitted with a separate cone type air filter). It doesn't leak oil or burn any as far as I can tell. Given the relative frequency with which I change the oil (more often than specified) I only look for leaks. I don't bother checking the level in the sight glass very often.

(cast iron) Bullet 500; after a few days in garage oil level (before start up) is between high and low level on dipstick; fill it up with 200 mls till level is on high mark dipstick; run bike for 45 minutes or so; on return check oil level in garage after 10 minutes; oil level now 1 inch above high mark dipstick; after 2 days still too high but seems to have gone down somewhat; I wonder: are we dealing with the same thing here?

Clement

Over a period of time the oil level in the cast iron bullet oil tank can drop because oil in the tank can drain down into the sump underneath the crankshaft.
Once the engine starts the scavenge pump returns that oil back into the tank leaving the level too high because of the extra oil previously added to adjust the 'low' reading originally shown on the dipstick.


Leaving the engine with the piston at top dead centre (preferably on compression to remove unnecessary pressure on valve train) will position the crankpin above the level in the tank preventing it from running downhill to pool underneath the crank.
What can also give an incorrect reeading is failing to wait for the timing chest to refil itself after a complete oil change. The volume it holds can drop the oil level off the bottom of the dip stick as the chest slowly refills itself lowering the level in the tank as it does so before eventually overflowing oil back into the oil tank.

Clement: No. The OP asked about the B5; this is the EFI Bullet, totally different.