RE: Ethanol warning (r1150) - 2

Can sudden loss of compression due to 4 (!) burnt exhaust valves be considered engine wear?
For me that is too much of a coincidence.
I did exactly the same trip, at the same speed, the next two years without any other particular maintenance to the bike.
I sold the bike at 120k and it was still running fine.

Back of the R1200RS owners handbook... Mentions E10 20190719_115927.jpg - Bild entfernt (keine Rechte)

My 1999 R1100RS ran on E10 Premium until traded for a R1200RS in 2016.

No problems. Just like my BMW cars

Perhaps you were pushing the bike too close to maximum power while riding at 200kph. That combination with the %10 alcohol may have been too much for the exhaust valves. These engines already run lean, alcohol doesn't help. My own R1150RS has only been fed E10 for over 200kkm, but I have never taken her close to 200 for any length of time. I did find the following in a search.

Some people have reported engines overheating when ethanol blends are used, suggesting that ethanol burns "hotter." This is a bit mysterious since ethanol contains less energy per unit volume than gasoline, and the flame temperature of ethanol is more than 40°C cooler than gasoline. The most likely explanation is related to the air/fuel ratio. Most engines are designed to run with an excess of fuel relative to the amount of air (a "rich" mixture); experience has shown that this leads to higher power output and cooler engine temperatures. When ethanol blends are used, newer engines are equipped with sensors to adjust the air/fuel ratio automatically. Older vehicles and small engines may not be equipped to do this, resulting in a "leaner" burn that may increase engine temperatures and/or reduce engine power. A simple adjustment to the fuel system to "richen" the mixture can often fix this problem.

That would explain what happened, so maybe a lean mixture is detected and adjusted systematically during services where E10 is used (no E10 here in Switzerland, at least I have never seen any)
And as I said, I had absolutely no power loss before that blast.

Can I add a suffix " Under Extreme Conditions" to the title of the post?

Kev

Zitat von Son of Sam im Beitrag #19

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When ethanol blends are used, newer engines are equipped with sensors to adjust the air/fuel ratio automatically.

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