BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Is it true the clutch side and the throttle side of the fuel tank are shaped differently? I'm struggling to see it.

If so, why are they asymmetrical?

It is.

It's pretty apparent looking down from above. My guess is so that the tank contours visually match the cylinders, which are not symmetrical from the top either. One is further forward than the other.

Look for the difference this way: the front of the seat has two "ears" that stretch forward; the seat ears are symmetical, left and right. Each "ear" fits into a recess in the tank. Look at the distance between the forwardmost point of the recess and the bottom of the tank: it's much greater on the left side.

Looks like thw wintertime posts are starting early

The tank cut is higher on the right side at the bottom, it leaves more room there for the intake snorkle.

mogu83 wrote:Looks like thw wintertime posts are starting early

Weather here is still nice ... my advice would be to get out and ride another month or so and save these up ... could be a LONG winter!

mogu83 wrote:Looks like thw wintertime posts are starting early

Wow, do we need ro run an asymmetrical oil as well to compensate?

That's interesting Bill. I agree with dbrick and DonC. Air intake. Thank you gentlemen.

MTBeemer wrote:Wow, do we need ro run an asymmetrical oil as well to compensate?

not necessarily - you can get away with balanced oil - BUT you MUST fill up witht he pump on alternating sides of the bike in a specific pattern to maintain the petro-chemical dis-proportionality within the tank.

On the 259 oilhead series the pattern was left, left, right, left, right, right, left, right. (then repeat). Pretty simple pattern because the oil heads were relatively well distributed above the line of the crankcases.

But I think the 1200 series pattern is: right, left, left, right, left, left, right, left, right, right, left, right right, left, right, left, left, right, left, left, right, left. (the repeat). That's the advice I got from my dealer when I hired one for a week.

Going on 4.5 years since I took delivery of this fine machine, and seems as if I learn something new every week. Thanks for the insight — and humor!

On another R12R forum, someone named "sup909" pointed out that the valve covers on all boxers are offset -- just look from the top view. I love the interwebz.

I think BMW started making them that way because of their intent in getting into NASCAR with all the left hand turns..... pretty sure.

Bill - the cylinders are offset - pretty much have to be since the BMW engine doesn't use a "simeased" (SP?) - ie - forked - connecting rod setup like Harley does. The connecting rod bearings for the two BMW cylinders run side by side - causing the offset.

Is there an aftermarket single-journal crankshaft that I could install? That would line up my cylinders and also give me the engine shake and potato-potato sound I have been looking for.

xprof wrote:Is there an aftermarket single-journal crankshaft that I could install? That would line up my cylinders and also give me the engine shake and potato-potato sound I have been looking for.

Absolutely!

However you gotta buy the Harley that wraps around it to get it.

Thanks, Snapping, but I've got a better idea: I'll carve one myself out of a block of cast iron with cold chisels...

Just go back with pictures in a time even footpegs are assimetrical.It was normal for BMW boxers all the time.Sitting on thise bikes like you are preparing right leg to cick someone a.... !

Standing behind my bike this weekend and thinking about this very interesting subject I took a look forward and sure enough you can see it from there. Easy as pie.