Need all kinds of info

[85mercb/m150]

How do you measure the hub diameter? The hub is measuring 4 3/4" od. I think it's a 1985 150 hp BlackMax XR2 ??? S/N A166483 or is this a 86? What is the WOT rpm range on these. And the gears, one has 14 teeth and the other has 28 teeth. Does this mean it's 2:1 gear ratio?

Thanks a bunch

 

[Gomer50]

Re: Need all kinds of info

On your gear ratio I was told devide your gears into your pinion gear and that will be your gear ratio 28 / 14 = 2.0 -- 28 / 13 = 2.15 -- 30 / 13 = 2.30

 

[j_martin]

Re: Need all kinds of info

Hub diameter is the diameter is the inside diameter of the LU bore that interfaces with the leading edge of the prop hub. Sizes are 4 inch and 4 1/2 inch.

Prop hub diameter at the leading edge is slightly under that, thus a 4 inch prop would be 3 7/8 inch diameter, and a 4 1/2 would be 3 3/8 - 3 7/16 diameter.

The trailing edge is usually flared, and larger.

hope it helps
John

 

[usskydvr]

Re: Need all kinds of info

Your serial # indicates it is a 1985. WOT is 5000-5500 RPM