Cylinder Head Carbon Deposits - BMW 1200 GSA
Three friends and I just rode London - Beijing on nearly identical 2007 BMW 1200 Adventures. On returning to England the bikes were turned over to a BMW garage for maintenance. All of them turned out to have significant carbon deposits on the cylinder heads - "where the piston comes towards the exhaust valve".
They getting stuck in with a wire brush and hope this will do the job. But I thought I'd search the net for similar problems and came across this string, so am adding this info for anyone collecting such data.
None of the bikes had mods to make them run leaner. We ran in very hot conditions across deserts and used low octane fuel where that was the only stuff available. However, on such occasions we usually added octane booster.
Hope that's useful extra input.
If it takes more than a wire brush, I'll let you all know.
In the meantime, it's fun to discover such knowledgable new friends.