And what is meant by 'wet'? Water ( most common use of term )? Oil ( what kind )? Dish soap ( hey, it gets wet too! )?
And what about the big concave washer? Concavity facing tailpipe, or the front of car?
And that washer has a small cutout - looks like it maybe had ( past tense ) a little tab that has over the years gotten lost/broken off - prolly originally used to bend over the large nut to keep it from backing out? Is it necessary to put new one in? Do fresh ones exist?
Inquiring minds, etc.
1982 Spider Veloce
1999 BMW R1100S