Yamaha tilt and trim brush dust problem

[FishStretcher]

For the 2nd time in 2 years I have had to remove my (original) Yamaha tilt and trim for my model year 2000 F100. I took it all the way apart last year, then reinstalled the brushes. It had packed up with brush dust, and the brushes only made intermittent contact, so the tilt motor slowed, then eventually quit. Banging with a hammer didn't fix it to any real degree.

It had the same symptoms this year, so I pulled it and sprayed it out with brake cleaner. I got what I think was a lot of brush dust out of it. I had greased all the retaining screws up pretty well last year, so R& R was easy, and I just squirted behind the brushes in the springs with brake parts cleaner, and the commutator bars. It runs like a champ again now.

Anyone else have this problem? I spent a lot of time fiddling with trim trying out props, and I play in an estuary a lot, with a lot of tilt up and down, but an annual brush cleaning (or 2nd time for a 12 year old motor) seems out of the ordinary.