Question about Motorcycle Oil

Discussion in 'Technical' started by TonyBKK, Feb 1, 2011.

  1. TonyBKK

    TonyBKK Ol'Timer

    Hi Guys,

    I'll confess I don't really know much about motor oil and usually just buy the best stuff I can find. I run my GSX-R on Motul H-Tech 100 Full synthetic which I'm told is one of the very best 4T motorcycle oils on the market. It's also very expensive stuff!

    In the case of my Kawasaki's I've trusted the recommendation of the service staff who until recently always recommended Shell Advance VSX Semi-Synthetic 4T motor oil. But Kawasaki Rama 9 recently changed motor oil from Shell Advance VSX semi-synthetic to Shell Advance AX7 and after a couple of track days the new AX7 motor oil turned to sludge so I'm a bit concerned and wonder if you guys can offer any insight about the difference in these oils.

    Here are pics for your reference:


    I know it's hard to read, but the old Shell Advance VSX is rated API SJ, JASO MA while the new Shell Advance AX7 is rated API SL, JASO MA 2

    I have no idea what the difference is between API SJ and API SL or between JASO MA and JASO MA 2

    I want to go talk to Kawasaki about the change but want to know what I'm talking about before I go there.

    Anyone know what the difference is between these oils?


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  3. mikerust

    mikerust Ol'Timer

    Don't know.

    Standard answer would be a coolant leak. Could it be the "sludge' was always there and the new oil simply flushed it out.

    Is there a difference between AX and Ultra? I couldn't find AX on Shell Thailand's site only Ultra.

    If staying wth Shell why not use Rimula Ultra. Commercial "diesel' oils have long been touted as the best for bikes with integral gearboxes.
  4. Maha

    Maha Ol'Timer

    Looking at Shell web site, it seems Shell Thailand sells the VSX ( and Shell Philippines sells the AX7 (

    VSX market text from Shell:
    Shell Advance VSX 4T
    Shell Advance VSX 4 is a unique semi-synthetic lubricant exclusively developed for 4-stroke motorcycles, providing excellent engine protection, cleanliness and superior clutch and gearbox operation
    - It is specially designed for riders of high-powered bikes who need a superior oil that protects and keeps their bike engine clean in all types of road conditions
    - Its balanced formulation means the oil retains its viscosity for longer and reduces oil consumption
    - The special formulation prevents clutch slippage and reduces clutch sticking after cold starts
    Smoother gear change
    - Provides excellent engine protection and performance, keeping engines cleaner for longer
    - It exceeds the requirements of international specification (API - SL and JASO MA) and all Japanese and European motorcycle manufacturers

    And AQX 7:
    Shell Advance AX7 10W-40
    Semi-synthetic 4-stroke motorcycle engine oil ideal for high-performance motorbikes. Shell Advance AX7 offers excellent oil-performance reliability, helping to protect and clean your engine and prolong its life. It also provides advanced control with smoother gear changes and an enjoyable ride by reducing noise and vibration. Shell Advance AX7 offers enhanced performance for standard motorbikes, underbones and mopeds.

    Key Features
    - Enhanced shear stability to dampen vibration and reduce noise
    - Enhanced protection against valve train wear
    - Special formula keeps oil in-grade for longer
    - Optimised friction control for smoother clutch engagement and gear changes
    - Removal of sludge and engine deposits

    So the sludge removal seems to be standard feature! :)
  5. KenYam

    KenYam Ol'Timer

    G'day Tony

    Simply said change back to another oil and check for similar sludge build up, as maybe you have a water leak. If no excess sludge present dont return to AX7 oil.
    I wonder how much on description of AX7 is sales talk. It aint healthy for sludge to be present in oil so this should ring alarm bells.

    Cheers Ken F
  6. monsterman

    monsterman Ol'Timer

    The Shell oils are group 3 and 4 oils and are not really semi synthetic at all , Shell have run into problems in USA when claiming synthetic qualities in their oils.. Motul Synthetic is a full group 5 oil and is completely synthetic

    It is probable that the ASX has extra cleaning detergent compound in and that loosened the deposits in the engine ..personally i would use another oil brand , Motul is the best in thailand or mobil1 , but castrol or honda products are OK too. In my Ducati here i use Motul or Mobil , in UK i use Putoline.
  7. TonyBKK

    TonyBKK Ol'Timer

    Thanks for all of the excellent feedback guys!

    I've changed the oil and filter and will do another track day with the Shell Advance AX7 and see how it goes. This is Liam's old ER6 and when I bought it, it only had 9000km on the odometer and I know he rode it gently and serviced it regularly. Since I've had it, it's only been used for track days, so ridden hard, but not for any great distance/duration. I was shocked at the condition of the AX7 oil after a couple of track days.

    Yes, it's quite possible that there's a small coolant leak that's contaminating the oil... Hopefully she'll hold together for the Pirelli Track Day on Sunday after which it may be time for a re-build...

    Thanks again for all of the helpful advice!

    Ride On!

  8. mikerust

    mikerust Ol'Timer

    Might be worth bunging in a small tube or half a tube of "local" Barr's Leak. We got some for 85 baht at the auto spares shop on the corner of Sukhumvit 58 or 56, I can never remember, up from Tesco On Nut . But if they have it maybe so does everywhere else. It worked on a Honda Civic which had a very slow coolant leak.
  9. brian66

    brian66 Ol'Timer


    API is the American Petroleum Institute which began grading oils at the beginning of the 1900’s
    The grading started with the designation SA and progressed through different S grades and now the latest is SN

    Current API grades include SN, SM, SL and SJ for petrol engine. All previous API service designations are obsolete. So any one of the above API categories is ok to use.

    JASO is the Japanese equivalent (Japanese’s Automotive Standards Organisation) of API and the MA classifications is to show the oil is suitable for wet clutches.

    So there are no problems mixing those two oils and they shouldn’t have caused any sludge to build up.

    If there is water leak it can only be coming from the head gasket or the water jacket around the cylinders or the water pump shaft may have a seal leaking between the water side and the oil side.
    This would be the likely place to leak I would say.

    If it were the head gasket the power loss would be noticeable and it would probably miss fire. If it is the water jacket the cylinder block will need replacing if it is so corroded the water is leaking into the crank case. This is unlikely at the age of the bike.

    If it is a water leak it should be obvious in the oil when you drain as the water will separate from the oil if you let it sit for a while.

    Synthetic oils can be mixed with standard oil as most synthetics are made from refined crude oil. Some expensive pure synthetics are made using a combination of elements and chemicals derived during the repeated refining process of crude oil. This oil has little or no additives. There are many “blended Synthetic oils” Which consists of around approximately 30% synthetic and the rest natural refined oil.

    But once you mix the oils together the additives in the natural oil spoil the true synthetic oil properties so you gain nothing, you may as well have used natural oil. The blended synthetics are a waste of money.
    Either use normal oil or pure synthetic oils. Both do a good job but one a better job.

    The claimed advantage of pure synthetic oils is its low temperature friction ability, its lack of additives and it maintains high temperature viscosity better than natural oils.
    I have used pure synthetic in all my racing bikes since it came on the market and every motor I have ever stripped and measured has very little wear considering the hard stress it has been subjected to on the race track.

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