Originally Posted by Lone Rider
Why are you interested in using the K & N?
Because the paper filters sometimes don't last 6,000 miles - mine have gotten wet and started to disintegrate early. And trying to find a paper filter every 6,000 miles is problematic in various parts of the world - as well as the price issue.
I've not had any negative experiences using K&N on my 650GS. Can't say I've sucked in outrages amounts of particulate matter - bike still doesn't burn hardly any oil between changes.
I have had dealers say the reason my bike is hard starting at altitude is because the K&N filter doesn't let air pass as freely as the paper filters. This is bullshit - they can't come up with a solution to the 2005 650GS hard start problem, so are using trial and error to come up with answers - which means you still pay, and the bike isn't any better after the fact.
In September, 2006, BMW came out with a service bulletin on this "hard start" issue - there's 2 throttle control spring replacements along with programming update to address it - whether it actually solves the problem when trying to start the bike above 3000m is unknown since the dealers in SA don't seem to know anything about this problem, or BMW's recommended solution.
Make sure you get the spring replacements and reprogramming done before hitting altitudes over 3000m. It runs fine at such altitudes - it just won't start if parked overnight at such heights.
Also, use lighterweight engine oil when operating for extended periods at such altitude.
Chiang Mai, Thailand