Hi, I'm setting off on my 800GSA (late 2013) in 2 weeks time, & will do around 2000 mile round trip. The bike had its 12,000 service 2 months ago.
No scottoiler fitted to the bike, so I was planning to take some chain lube and also some engine oil just in case for top ups.
The owners manual recommends Castrol ... but the grade states 15W - 50. On my 650GS I used Castrol Power 1 4T 10W - 40.
Recommendations for the oil appreciated.
OK, let's see if we can help you.
(1) Don't worry that the owner's handbook says Castrol but you can only find say, Texaco or Repsol or Esso. Rather like bottled water, it doesn't matter which oil company made the oil or whose bottle it comes out of. More than anything else it's just a branding exercise.
(2) You have seen in your owners handbook that the recommended oil differs between your 800 (15W-50) and your former 650 (10W-40) that is not unusual nor anything to worry about. Put simply, they are different engines in different bikes, for which the manufacturer has recommended different grades of multi-grade oil.
(3) Spain and much of southern Europe has higher average annual temperatures than we do in the UK or say Finland. The manufacturers (in your case BMW) may well recommend a different grade of multi-grade oil for bikes in Spain, than they do in England and / or for those sold in Finland. That is, by-and-large, the reason why you'll find different grades sitting on petrol station shelves as compared to the UK.
(4) Don't worry about it. 100's if not 1000's of Spaniards ride motorcycles and all buy oil, without too much difficulty. You can do the same, from just the same places as they do. Whether that's a bespoke motorcycle dealership or a humble two pump fuel station or Repsol's flashiest multi-pump and restaurant filling station, it makes no odds.
(5) Walk in and look at the bottles of oil on sale. More often than not the engine oils for motorcycles will have a picture of a motorcycle on them them. That's a great start. You might then find 4T and 2T, they are simple designations of the oil between 4-stroke (4T) and two-stroke (2T). Yours is a 4-stroke motorcycle, so head for 4T oils. Nearly there.
(5) Your owner's handbook maybe listed a whole range of different mult-grade oils you can use. Some do, some don't. You may well find, sitting on the shelf, an oil with a multi-grade that matches one of the alternatives. If so great, buy it. Job done.
(6) No? OK don't worry too much. Just buy the nearest 'closest to' alternative 4T oil you can find. You can mix multi-grades together. For instance, a 50-50 mixture of 10-40 with say 20-50 will produce 15-45. That nobody (maybe) makes a 15-45 doesn't matter, your bike will be fine. Trust me. Job done.
As to the bit about chainsaw oil in Scottoilers? Yes, it works fine. But as you don't have a Scottoiler, you don't need to worry about it. Just store the knowledge away for a time when do fit a Scottoiler, if and when you ever do. Just take a smallish can of chain lube (or even a small pot of gearbox oil and something to apply it with) with you. Spray the chain if it looks dry on arrival each evening. Job done.
One tip if you ever own a bike does not have a center stand: Learn the trick of squatting behind your bike and lifting the rear wheel upwards, using your knee, usually by levering it up under the exhaust pipe. You do not need to lift the bike far to spin the rear wheel. It makes apply the chain lubrication much easier.... Or find a suitable stick to prop the bike with.... Generally a knee is easier and quicker. The same trick works if you have a puncture and need to find the nail or indeed for any task that might involve you spinning the rear wheel on your own.