Funny story to add to this.

My buddy decided he would clean the motor brush rigging and all with contact cleaner.

Well,he didn't let the cleaner dry long enough,turned on the unit and ran it.
A few sparks turned into a nice little fire.
All that oil and carbon dust burns good!

Shut the unit down,frantically searching for a fire extinguisher,which happen to be down at the bottom of a ship ladder.
Finally got it put out.

Got to love adjusters sometimes.;)