I'm replacing my 3 blade prop on my 48 hp Evinrude. I got the prop from Gander mountain and a hub kit for it. The kit came with a plastic splined washer with two little studs on it. It also came with a round plastic washer with two holes that the first washer studs fit into. On the directions for installing it says make sure the thrust washer is installed. i figured out the thrust washer goes on first then the prop then the two washers that came with the hub kit. But when I try to use all these parts the nut doesn't fit on the shaft. If I just try to use the splined washer then the two little studs are the only thing that goes against the nut. If I just use the other washer it isn't splined and is loose on the prop shaft. I guess my question is, how important is the thrust washer? I 'm pretty sure I shouldn't install the prop without it. How much clearance do I need between the prop and the motor? Not the blades but the round part that fits in the motor. I've tried doing a search on the internet but can't find anything.