I had to remove my brush blocks to get to the slip rings and clean them on my Onan 5500. It wasn't a big deal for me. A couple of screws and the whole brush assembly came out...the brushes were under slight tension from the springs, but not so bad that they came flying out. I simply sprayed carb cleaner on the slip rings while the engine turned and then replaced the brushes. It's been running and powering great ever since. I did find out the truth of the rule of less than 1/4 tank of fuel, the genset will shut off....... ;-)
