1963 Mercury 650 thrust hub/washer question?

[MPrimeaux]

Hello all. I'm restoring a '63 Merc 650 (Serial Number 1543001) on a 14' 1957 Fleetform runabout that weighs around 400-450 lbs. The engine came to me with a pontoon boat prop and I changed it out with what I believe to be a quicksilver stainless prop (48-72762A-4 19P). Noticed that when I tightened the prop nut, the prop would not turn. Loosened up the nut just a little and the prop turns freely. Got me wondering if someone put the wrong thrust washer on engine. I'll attach some pictures of what I have. Any input would be appreciated.

 

[jimmbo]

It looks like the Thrust Washer you are trying to use has a Taper, but the Prop Shaft doesn't.

The Parts Diagram shows what looks like an inverted cone as a Thrust washer and then a cupped washer.
What was on the old prop?
Perhaps a Merc Dealer may have some under a pile of Dust. Otherwise you might try running the Part #s on E-bay

A 19 in pitch sounds like quite a bit of prop for a 65hp

 

[MPrimeaux]

It looks like the Thrust Washer you are trying to use has a Taper, but the Prop Shaft doesn't.

The Parts Diagram shows what looks like an inverted cone as a Thrust washer and then a cupped washer.
What was on the old prop?
Perhaps a Merc Dealer may have some under a pile of Dust. Otherwise you might try running the Part #s on E-bay

A 19 in pitch sounds like quite a bit of prop for a 65hp

That's what I was thinking too jimmbo, the tapered thrust washer is what was on there with the old prop. I am just unsure about what could be interchangeable. Thought maaayyyyyyyybe there was a chance that someone would have a, "yeah it'll be fine" answer. Probably wishful thinking. I definitely don't want to tear anything up. I JUST got the engine running after spending a good deal of time and money on NLA parts. As for the 19P prop, yes it probably is a bit too much prop, but I paid $40 for it. My thought process was the boat is actually rated for a 40hp and weighs a whopping 450 lbs, but we'll see. It will be a cheap spare if nothing else! Thanks a bunch for the input !