oil 75 850

Hi, Question about oil's. Have been running castrol actevo semi synthetic/blend in my 75 mk3. Don't like too switch oil's once I start but couldn't get castrol. I used lucas semi on last oil change, went for a 200 mile ride. Next day I out in the garage and there's puddle of oil under my bike. It is leaking from primary cover and was wondering if changing oils might have messed with gaskets/seals, as in different detergents and such. any suggestions about oils? Thanks John ( been running castrol for a number of years)

Oh oh!!! :roll:

jnorton75 said:

Next day I out in the garage and there's puddle of oil under my bike. It is leaking from primary cover and was wondering if changing oils might have messed with gaskets/seals, as in different detergents and such.

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Where exactly is the leak coming from?

The Mk3 primary case joint is pretty much oil-tight under normal circumstances if the gasket faces are in good condition, so unless the primary was considerably overfilled, then I think the problem is not likely to have been caused by the change of oil type, it's more likely a seal has deteriorated, probably due to age.

To add to this - is the oil on the floor the new synth engine oil, or the type of oil in the primary. ?
(these are quite separate compartments, and generally have different types of oils in them.)

You can usually tell by the color smell taste which oil is what when you find it on the floor.
(we don't recommend tasting it !).

Did you put the correct quantity in, if overfilled it may well remind you of this...

Don't rule out that it may be gearbox oil too - does it have that sulphury smell to it ?

Rohan said:

To add to this - is the oil on the floor the new synth engine oil, or the type of oil in the primary. ?
(these are quite separate compartments, and generally have different types of oils in them.)

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Not necessarily where the 850 Mk3 is concerned as the recommended oil for the primary case (due to the automatic primary chain tensioner) is 20w/50.

So we will have to wait to hear if the OP changed the oil in the primary too.
And used the correct quantities....

Thanks Guy's for the reply's,been working late so not much time to reply. I have a feeling I have a bad seal. On the mk3 the oils are the same. (motor,primary) Both were changed and proper amounts put in. I did notice I had a little extra oil in the primary when I changed the oils . Should have known then something was wrong,but I wanted to ride