The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: georgesgiralt on July 06, 2013, 04:04:58 PM
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Hello !
Yesterday I had to go to a funeral. 450 km going and back.
Before going I topped the oil to the MAX setting.
I went by road, running between 90 ~ 110 km/h. Then I went back mostly by the same road but I took the motorway for the last 100 km. On the motorway it was 130 and a try up to 150 km/h.
At home, the oil level is exactly in the middle between MIN and MAX marks on the dip stick.
So around a litre per 1000 km.
The engine has been put with new rings around 3000 km ago and the valves had been checked for leaks and found without.
As the weather was really hot (above the 30° Celsius) I wonder if this is the cause or if the motorway ride at high revs are to blame ?
It is strange because I use her for my daily ride to work (city and a little of motorway but limited to 90 km/h ) and she does not burn oil at all.
What do you think ? What should I do/check ?
Thanks a lot for your advices.
Oh, by the way, oil is Motul mineral 20W50 so the correct one. I think.
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I don't think it's strange that a high speed run increases the oil consumption. High speed will always do this especially when filled to the max. level. Many report increased oil consumption when filled above half way. Even BMW indirectly acknowledged this by issuing service guidance that oil should not be added until the level reaches the min. mark.
I wonder how much oil would be consumed if you did the same run starting with the level half way between min. and Max. It would still be more than commuting but maybe less than you experienced.
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I'll bet you have a small amount of oil on the floor under the left carb tomorrow morning .
I cut a small portion of a copper pot scrub pad and placed it in the housing over the crankcase breather valve and it has reduced the amount of oil that goes through the ventilation system into the airbox .
Oil comes out in an atomized state and the copper pad gives it a place to collect on and gets back to the sump after the engine is shut down .
I've also been using a semi synthetic oil by BMW, that seems to help as well .
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Many of these twins will blow oil through the breather and into the carbs when filled to the "Max" mark. I leave mine halfway in between MIN and Max and very little oil is pumped through the breather and into the carbs. With the oil at this level in the sump (halfway between) I've seen oil consumption of about half a pint (8 oz) in 1500 miles/2500 km with running the bike often up to 110km/h - 130km/h speeds.
Often, if the oil level is put up or above MAX, oil pumping the breather will be higher until the level is about halfway, at which point the amount of oil consumption will greatly decrease or stop altogether, once the engine has found its "level". Those large pistons going in and out together tend to pressurize the crankcase, especially at higher rpms, which contributes to more oil mist being pumped through the crankcase breather valve and into the airbox & carbs.
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With all my Airheads, I keep the oil level at the mid-point between Max & Min indicators. Far less oil mess to clean up and, so far, no degradation in oil levels even after a lengthy spirited run.
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When I rode a lot of miles, if the R65 were filled to Max, it used oil until it reached the mid point and then stayed the same for thousands of miles. Even when ridden for several days consecutively for long distances at speeds a little above the limit (usually stayed below 90 for all day travel) oil level never reached Min. Statues of limitation have expired for any violation officer.
Bob
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You'll notice a smoky startup if your breathers are dripping oil into the carbs. I've decided to move mine out the air valve hole in the back of the airbox and to a filter aside the rear fender. If my breather is spitting oil I'll notice it at the filter or the clear vinyl tubing that runs to it.