need information on a hub

[waterdog 101]

I need to know, how to tell if a hub is large or small. if they were side by side i could tell. but a guy has one that i want to buy, he lives 2 hours away. and he don't know either. it's size is 13 and 3/4 X 21" pitch. i need to know the hub size to know if it will fit a mercury 90 hp. it was on a mercruiser alpha one. please tell me if you know. thanks

 

[Dhadley]

Re: need information on a hub

We'll assume it's a 4 blade prop since you didn't really tell us much about it. Most 13 3/4" diameter props are meant for use on a 4 3/4" (typical V6) gearcase. But in the Merc line the prop hub for a 4 3/4" gearcase and a 4 1/4" (typical 4 cyl) gearcase both use a 15 spline.

We have used the OT (over / thru) 13 3/4" diameter props on the smaller gearcases but they then become strickly a thru hub exhaust prop. On boats that have a pad or an otherwise performance type hull it's worked out pretty well.

Just measure the forward (motor end) of the barrel of the prop, either where it steps down or just before the step. The one you want to buy should be the same as the prop you have now. That measurement will tell you if it will fit your gearcase without rubbing.

It would really help to know what brand and style prop we're talking about.