ORIGINAL: Jimmy Skids
Walt,
When having a knurled metal back plate I like to use a nylon washer (found at OSH) in between the back plate and the thrust washer. I tighten the nuts as you do. I also check the nuts for tightness every few flights. Since I started doing this my thrust washers have really held up.
SooprDink,
I would check with Richard at YS parts and service. His number is (775) 267-9252.
Jimmy Skids
Jimmy,
I'm not familiar with the abbreviation "OSH". What type of nylon washer are you using? Is it a thin washer with a diameter the size of the props thrust washer?