Just a topic that for discuss that people like to do their own maintenance

[aleh314]

For the engine oil yes it is 10w50

I believed that bmw using the same 541 oil fiter that fits R nine T and oil cool engine.

For the gear oil and final drive oil that is my question.

I have been using the 75w90 on R nine T and R1200GS oil cool for many years without a problem.

Just wondering can i also use 75w90 for the R18 instead of the 70w80 that factory recommand?

Does anyone try that?

 

[Gaylord Poe]

For the engine oil yes it is 10w50

I believed that bmw using the same 541 oil fiter that fits R nine T and oil cool engine.

For the gear oil and final drive oil that is my question.

I have been using the 75w90 on R nine T and R1200GS oil cool for many years without a problem.

Just wondering can i also use 75w90 for the R18 instead of the 70w80 that factory recommand?

Does anyone try that?

I'd recommend "going by the book" for all fluids during the warranty period - and save your receipts (I even take a couple of pics of the servicing in progress). It simply makes life a bit easier (although not impossible) should should you have a warranty claim and a reluctant-to-help dealer.

 

[theMucker]

Ya know... I just now had to look up how long the warranty lasts. Three years! That's pretty good. Personally, being a professional mechanic, I've never paid much attention to manufacturer's warranties. Not that I wouldn't put in a claim if the occasion comes up AND assuming that I have confidence in the wrench's at the local dealership. Maybe I've lived a charmed life, but the few times that I have had to put the warranty to use, on any of my motorcycles since 1971, there has never been an issue. Maybe I've just had great dealerships.
If I find that I simply MUST do some non-OEM alterations, I go for it. The R18 has a hell of an engine. It just flat performs. But I'm already thinking... what if it had more displacement? How about more compression? Ported heads are always a good thing. Is there such a thing as too much of a good thing? Hell NO!
Will the warranty stop me from twirling wrenches? Sh*t NO! While my Indian Roadmaster was under warranty the OEM produced a big bore/hot cam kit that was only supposed to be installed by a dealership. My local dealer sold me a kit and I did the install, while also porting the heads myself. It's YUMMY!
Lets see what sort of high performance goodies show up in the aftermarket. This opposed engine is soooooo easy to work on. Beefier pistons can't be too far off........

 

[David R]

I was thinking milking the head? Or the top of the cylinder to increase compression?
David

 

[theMucker]

I was thinking milking the head? Or the top of the cylinder to increase compression?
David

I assume that you mean milling the head or cylinder to boost compression.
That's the "typical" method to boost compression. But the method used will depend on the design of the components. Much of the time, cutting the heads to increase compression is the best method. But it depends on the design of the pistons and cylinders. Is there a tight-fit "squish band" around the piston head's circumference that allows for a closer fit? Or can a boost in compression only be safely done by increasing the amount of the piston dome's occupied volume in the combustion chamber?
These are the questions that must be answered by the guys with the budgets that allow for performance increases through parts swapping or machine work. Personally, I've cut heads, cut cylinders and machined pistons to boost compression. Most of the time, that last method is tied to expensive altering of the combustion chamber volume. Cutting heads or cylinders to boost compression requires that the pistons won't come too close to the cylinder head material at TDC for the pistons to make destructive contact. That's a VERY common method used in American hot rodding. Let's see which of the above methods works with the R18.
For what it's worth... MOST OEM manufacturers claim a compression ratio that's VERY conservative. Usually, it's bullsh*t. And that's because they're producing engines that have to ingest gasoline that the modern world would choke on, yet they hope the third world will allow for longevity beyond the warranty period.
I've built engines that claimed 9.5:1 or 10:1 compression while stock, but after doing the measurements and calculations, they were far below those specifications. If you are a manufacturer making a motorcycle for Bolivia or El Salvador that you hope will sell, you will claim it to be a performer BUT it has to survive on low octane, barely combustible swill and you will lie where you have to. Those of us that can rely on better fuel can usually do better than the OEM's CLAIMED compression ratios.