Why is the DOHC oil fill on the Right side?

[Clem]

2012 DOHC R1200R 20,000 happy ones, and counting.
May seem like a silly question. What difference does it make? The window is still on the LEFT. I have asked 3 dealers and gotten 2 different answers and one honest "I don't know!" One said BMW just changes things on a new model to make the customer feel like it's different from last model. The other dealer said, with a straight face,"It's easier to pour in oil on the right side with it on the side stand." If you have to say something, Kudos for imagination. The dealer who said he didn't know added that BMW engineers always have a very good reason to make even the slightest design changes. Too many German GS riders removed their center stands??? So, what do you guys think? Join the fray.

[Catchina]

Well if you're going to add oil while on side stand (bike leaning left) it is easier to work from the right side.

[BoxerSteve]

I wondered the same thing, sure seems like it makes more sense to have it on the left side where it used to be. That way, you can easily monitor the oil level in the window as you add oil. With it on the right side it is more difficult to do that.

Maybe the newer engines won't need oil as often?

[Bill Stevenson]

This is just a guess, but as it makes little/no difference in terms of the functionality of the motorcycle, the change could have been made to accommodate a machine tool set-up or ergonomic issue during the manufacturing process. The sidestand argument doesn't seem likely because the bike needs to be level to gauge the amount of oil to add.

[MTBeemer]

......... the bike needs to be level to gauge the amount of oil to add.

I do not think that BMW moved the fill hole to the right side to facilitate adding oil while on the sidestand. If that were the reason, then the sight-glass would be on that side as well..... but, no reason they could not design a bike with a glass or dip-stick that was calibrated for use on the sidestand.

[deilenberger]

One of those rare cases where the dealer is probably right - with their guess that BMW did it because it's a new engine so it should look new.

I was showing an R12R friend how to check his oil and top it up (he was about a quart low..) and the stupidity of having the filler on the opposite side from the window was striking. Good reason to keep my pre-camhead..

[Bamblys]

I know there is a real reason, I read it somewhere. Maybe even owners manual. But it's nothing stupid like making bike look newer. I just can't remember. I know it made sense at the time i read it.

[roger l]

If the bike is on its side stand and you put oil in on the left side some of the oil will just pool in the left side valve cover. All of the oil will not run into the sump until the bike is tilted up straight. If the oil is put in on the right side all of the oil will run into the sump. This is all mute because the bike needs to be on the center stand to check the oil level anyhow.

Just a thought.

Roger L

[Clem]

This is all mute because the bike needs to be on the center stand to check the oil level anyhow. +1 roger1
That's right, it's a mute & moot point. I have worked at a solution to topping up the oil by myself. Knowing the oil sight glass shows about 500cc or half a quart difference, I use a 500cc container with increment markings to prevent adding too much. I also have an 8X10 mirror propped up against a milk crate and a light on the window so I can actually see the rise in the sight glass window as it fills. Don may not have the most tactful way of saying it, but he's right on the money this time. "The stupidity of having the filler on the opposite side from the window was striking." +1 Don

[Oaktown]

I've no idea why the change in oil filler location to opposite the sight glass, but I don't care because for me the two are unrelated. I changed the oil (Motorex) last Sunday in typical fashion: Remove drain plug, loosen filter and puncture it three times with my Makita right angle impact and #10 screw (fits easily between the sump and waste oil container), go inside and watch football game, replace filter after adding 200-250ml to new filter, use 500ml Pyrex lab beaker to fill to 3.7l total, operation complete. Ride bike to warm, let oil settle and the level is directly over the red dot in the sight glass. I use the sight glass during the next 6,000 miles to ensure I have the correct oil level, never to determine how much to add @ change time. To each his own.

[Boxer]

It may be that because every few miles you must stop on the side of the road to add oil and it is safer doing it on the side away from traffic. In England they don't use so much oil so it doesn't matter.

[badbs101]

This is all mute because the bike needs to be on the center stand to check the oil level anyhow. +1 roger1
That's right, it's a mute & moot point. I have worked at a solution to topping up the oil by myself. Knowing the oil sight glass shows about 500cc or half a quart difference, I use a 500cc container with increment markings to prevent adding too much. I also have an 8X10 mirror propped up against a milk crate and a light on the window so I can actually see the rise in the sight glass window as it fills. Don may not have the most tactful way of saying it, but he's right on the money this time. "The stupidity of having the filler on the opposite side from the window was striking." +1 Don

You have got to be kidding us about your oil filling routine?!?! If you really do all that just to top off oil, I believe we may have just been introduced to a new level of OCD.

You're spot on with the mute/moot comment as "mute" is commonly misused but didn't your momma ever teach you it's impolite to correct people?

[deilenberger]

I know there is a real reason, I read it somewhere. Maybe even owners manual. But it's nothing stupid like making bike look newer. I just can't remember. I know it made sense at the time i read it.

PLEASE find this for us.. I'm intrigued.. since there is no possible reason I can think of..

[arp]

The camhead has a breather hose on the LHS cylinder head:

http://www.motorcycle-usa.com/616/4982/ ... -2010.aspx

Maybe to prevent oil getting in it during filling they moved the fill port to the RHS?

From a post over on ADVrider - http://www.advrider.com/forums/showthread.php?t=809270:

"That hose is an engine crankcase breather. It's used to ventilate the crankcase gases/pressure into the airbox. On my camhead, the lower cam also has an impeller that is likely used to sling off oil so the intake doesn't consume oil from the sump."

[Clem]

Not correcting, Agreeing with roger1 100%! +1 Mute rings clear to me, as I've never heard of anyone checking oil level on the side stand, and thus doesn't need to be considered.
True, my OCD flares, but using a mirror is obsessive?? LOL! Don't repeat that in front of ladies. Read some complicated oilhead valve adjustment procedures.
arp, good post! Previous boxer had a breather/vent hose,also. Getting oil in airbox.BTDT.@High rpm sightglass and filler cap blew out of R1100S boxer B4.(not at same time) Over fill is NOT good.

[deilenberger]

The camhead has a breather hose on the LHS cylinder head:

http://www.motorcycle-usa.com/616/4982/ ... -2010.aspx

Maybe to prevent oil getting in it during filling they moved the fill port to the RHS?

From a post over on ADVrider - http://www.advrider.com/forums/showthread.php?t=809270:

"That hose is an engine crankcase breather. It's used to ventilate the crankcase gases/pressure into the airbox. On my camhead, the lower cam also has an impeller that is likely used to sling off oil so the intake doesn't consume oil from the sump."

If by "LHS" you mean the PORT side.. the design is about identical on the pre-camhead engine. LARGE rubber tube breather from the cylinder head to the bottom of the airbox with a fan goober on the end of the camshaft that works as an oil seperator or something.. on the hexhead (pre-camhead) it's high enough that oil won't get into it even when filling the engine. The hose runs UP from the cylinder head to the airbox.. and is located at the lowest point on the airbox.

[mogu83]

You guys should have saved this thread for the middle of the winter, when we could really get into it. Still some great riding time (some say the best) in the northern hemisphere, not the time to be on a keyboard.

[Clem]

Harry, I really admire your sentiment. Hats off to you, Sir. Spoken like a man who loves motorcycling as much as anything. Hope you don't get any snow until Christmas. Make hay while the sun shines.

[Dr. Strangelove]

Having it on the right allows the filler to pour oil w the left hand and not spill the Kool-Ade in the right.

[Clem]

And now on the Wasser GS, the fill and sight glass are both on the Right side.
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