Mercury prop not fitting mercury outboard

[rmcustoms]

Hello all, I have a '89 mariner magnum II 150hp outboard. The motor was in pieces when I got it and just had the entire thing rebuilt. The only thing I was missing was the prop. I ordered a mercury 21p acording to the prop finder. My issue is... should the prop fit inside the Hub on the lower unit or be the same diameter? I'm not even sure it's touching the thrust washer.

 

[Bondo]

Ayuh,... It's close to the same diameter, but not touching,....

 

[rmcustoms]

No Title

It bottoms right out onto the lower unit. I took a pic pulling it back slighty. When the prop is seated I can stick a screwdriver down and wiggle the thrust washer. The hub isn't even close to touching it.and the prop itself rests on the the lower unit

 

[Bondo]

Ayuh,.... My guess is, ya got the wrong thrust hub,....

 

[Frank Acampora]

The prop is certainly incorrect for that lower unit. Are you certain the engine has the correct lower unit? Mercury made a small diameter lower unit for the 90 HP engine. Measure the diameter of the lower unit bullet. I don't remember exactly but the larger gearcase is 4 1/4 inches. The prop may be off an IO lower unit which is larger than the outboard lower unit.

 

[Chris1956]

The smaller diameter of the very front of the prop (about 3/8" deep) is supposed to fit into the gearcase. The rest of the hub of the prop is supposed to be the same size as the gearcase. It looks like the smaller part of the prop will not fit into the gearcase. I am not sure why that would be.

 

[rmcustoms]

Thanks guys. I checked the part number on the prop. I ordered the right prop but the wrong one came in the box. Thought I was losing my mind