im not sure what washer you mean?the advancer goes straight onto the crankshaft end and its held by a bolt,i think you mean the big nut on the end?you must have that nut,it has two square slots that line up on the end of the advancer and locates on those two prongs,by the way dont ever use a spanner on that big(fake nut)to turn the engine over with the spark pugs installed,you will break the little lugs or bend something,i havent got a photo of that nut on hand,someone might post one if they have one?heres the advancer itself,the fake nut locates onto those those two protruding lugs.
this shot just shows how if you dissemble the unit to be sure to align it the way it came apart,itll be 180 out otherwise and wont run unless you switch the blue and yellow wires over,lets not get into that,too much info?