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Oil, bubbles, more oil

Discussion in 'Technical and Troubleshooting Torque' started by generalyuehfei, Oct 10, 2005.

  1. I have recently changed the oil (@10k) in my bike to Motul 5100 10w-40 as I do not know what oil the previous owner used. The bike has only travelled 11k.

    When I changed the oil, the level seemed just a tad over the max (after running the engine for 4-5mins to get through the oil filter), and I have ridden it to work for a week now but noticing a lot of bubbles (2 rows of them) in the oil indicator. Nevertheless, I 've seen some comments here that it may be condensation which is fixed after a big ride.

    After a 250k run yesterday, I parked it on the centre stand and checked the oil - bike still hot - lots of bubbles and the oil level was now nearly at the top of the glass way passed max.... Aren't bikes meant to chew some oil, not produce more of it? :LOL:

    My questions are, will having too much oil cause a problem? Do the bubbles indicate there is a problem?

    Regards, Nick
  2. Yep, too much oil can cause foaming, and can lead to inadequate lubrication (ironically).

    The foaming can be caused by 'splashing' of engine components in the oil.

    Did you add any aftermarket products to the oil?
  3. None at all. I wonder if it has anything to do with the old oil :?: (whether it is mineral, semi, or full synth). This is a small part of the reason why I used a semi-synth motul oil.

    I will put the bike up at home in a cold state and drain some oil on the weekend. It's the bubbles that are concerning me?
  4. Oil bubbles are common enough. Heat and bubbles make the apparent oil volume increase.
    Check the level when cold.
    Should settle back to the full mark.

    There is a definite difference between a stream of bubbles and a foamy froth though. Only the froth would be of concern.
  5. Thanks guys...

    It is definitely a stream of same size bubbles each less than 1mm and at worst case 2 rows.

    Will do as suggested

  6. The vfr800 has a centre stand.
    Are you checking the oil level with it on the centre stand?
    Thats how it is supposed to be observed through the glass.
    On the side stand it will show more.
  7. On anything even remotely modern, that would require overfilling by a matter of litres. Sumps are deep, these days.
  8. Yep - on the centre stand. The vfr800, hen on the side stand - as it leans left and the window is on the right - it actually has no oil in the indicator. Checked it just before and although it has dropped a little since hot and the bubbles have disappeared, it remains above max. Will drain some oil and get it within levels and start over on the analysis.

    Could the bubbles indicate a gasket problem whereby air is getting in? I'd imagine I would also see loss of oil and a puddle on my floor if that were the case.

  9. I think you worry too much.
    Drain a fraction out then ride the thing and forget about the problem because there is no problem.
  10. Ditto on Smee's comment. Bubbles in radiator can indicate a gasket issue.

    In the oil, the damn stuff is being thrown around at high velocity - to expect a smooth consistancy while running is just expecting too much. A blown gasket will usually show up in other areas - hot running the most common.
  11. Just being pedantic here but on the centre stand isn't the way to check the oil level. Get someone to hold the bike level whilst it is sitting on its own 2 wheels. You will find the oil level will most probably be spot on. Centre stand readings throw it out a bit.