By: William Wade
Two weeks ago I purchased a 1986 K100RT. I purchased a BMW oil filter and took it with me to the local Autozone(tm) Store.
I found a stamped steel filter tool (OEM oil filter "B" cap wrench #25401) for #2.99 that fits almost perfectly. It is a tad too tight and after installing the filter I found I had to wiggle it back and forth with the 3/8's drive extension while gently pulling down to remove it. I have since removed all of the paint on the inside of the wrench to loosen it up a little.
I have no financial or personal interest in Autozone™.