[quote=Big Yellow Tractor;243199]Colin
I do not know your bike - if it works for you- fantastic -
My not being able to find a straight answer to my oil questions for my bikes, I spoke to Pro's at Silkolene, Castrol etc as well BMW Tech. (as I have an 02' Dakar and a '04 1200 I wanted to really know my options) -
The outcome for my bikes was that the boxer engine is quite happy with either mineral, semi or full synthetic as it has a dry clutch-
However, since the Dakar has a wet one Silkolene, (who make bike-specific oils) BMW, Castrol Oils and two independant mechanics of amost 60 years combined experience on bikes have told me the same thing- that is not to use the fully synthetic one in that bike due to a very high probability of clutch slip. I am not an oil engineer so I am happy to accept that and have stayed with semi in the dakar and full synthetic in the 1200gs. We each must do our own research -

Some have said 'if it goes in' or 'if it fits then it's fine' - I do not agree with that! it may well have consequences anyone might prefer to do without. In the end- it's your bike so it's your call!

And depending on circumstances, it would be fair enough to say that some oil is better than no oil -says he- having put some semi synthetic engine oil into a Mauritanian army 4x4 front differential . It had struck a rock and cracked- and he was trying to get back from the border to NCK- I saw him the following year and he told me my 'repair' with instant metal etc had held- (good job too as he let me back in with a nice glass of mint tea and a smile!)

Sure, we each need to do our own research and make our own choices....which is what the OP is doing here. I'd defer to the manufacturer in any case, and I wonder why the OP is asking here rather than doing so.

My very personal experience: I stay away from synthetic, semi AND dino oils which claim to have friction modifiers, mileage enhancers, energy conservers, or anything of the sort. It is my understanding that these can cause wet clutches to slip; note that the use of such additives is not uncommon regardless of the source (synthetic/mineral) of the oil itself. I use other synthetics lacking this designation indiscriminately in both my bikes without any sign of slippage.

Mileages vary (so to speak).

Mark

There's a very simple reason why I am asking here...............

When you speak to suppliers they have a theoretical view in many cases. When you ask in a forum like this, where people are users of products in a whole host of conditions and circumstances, then you tend to get a much more accurate reply.


Chris

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"Life is too short to drink cheap wine!"

Chris, this is my attitude to oil.
If your engine keeps the oil to itself and does not share it with clutch or gearbox (like most old Brit bikes and airhead BMW's) then the oil is relatively unstressed and you can use mineral, semi?? what ever that is, or fully synthetic.
If your engine shares oil with the clutch, then avoid oils that claim to be energy conserving. (1970 on Triumphs for instance).
If your engine shares oil with the gearbox, gearboxes really chew up oils so they 'need' synthetic.
Add to this a need to above all have an oil of the right viscosity and with the right additives for your engine. EG an old flat tappet engine ( any old brit bike needs 20/50 SG only rated). A modern Japanese bike will need synthetic (for the gearbox) with very little zinc ( to protect the EFI sensors and the catalytic converter).
If the seals are in good condition and made for synthetic oil there should not be any problems with leaks.
If the clutch has grip to spare it probably will work with any oil.

Avoid any oil that claims to meet many specifications..
An oil specification is a MAXIMUM rating that it guarantees NOT to meet. SG has the most zinc and anti wear properties of ANY grade. an oil that claims to meet SF SG SH SL will not meet the lowes grade ( think SL)
SF and SH can have up to 0.010% zinc, SG 0.012% everything else is LESS.
It so happens 20/50 oil or THICKER is allowed to have more zinc than the specification suggests, but does not need to have ANY anti wear ingredients AT ALL to comply with the rating ( same as the rest).
All these rumours about slipping clutches and leaking seals are being spread by people with slipping clutches and leaking seals.

oldbmw

Thank you, a concise and easy-to-understand explanation. Much appreciated.

Chris

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"Life is too short to drink cheap wine!"