Prop size stamp?

[Lt1z350]

Bought a boat and it’s got a merc xr4 on it which told is a great motor for its age so happy with that. Owner told me on this Norris craft 1750 it did around 55/60 mph and comes out of the hole hard enough it scared his wife to death lol. I’m curious if this is a good prop still cold here and fixing a few things before go out so no idea on rpm yet and if in the engines idles window.
It has 4 blades which I read is good on certain boats helps steering maybe better gas mileage as this isn’t an efficient one I read.
One sticker left but cannot find a stamp on it or id as of yet and haven’t taken it off to look. It’s a stiletto stainless steel and was hoping maybe someone here knows not to bother taking it off to look on the other side for info or that’s where it might have a stamp.
Thanks

 

[Chris1956]

Gee, remove the prop and grease the propshaft. That way it won't corrode on.

Normally a fast boat uses a 3 blade prop. That blade looks to be high performance, so it may be fine. You will need to try it. SS props can be had for all prices on the internet, but usually cost at least $300, so you do not want to replace it unnecessarily.

I suspect the seller exaggerated the speed and/or power. An 150HP XR4 is a good motor, and on a 17 footer, will give good performance. Just maybe not as good as specified.

 

[merc850]

I've seen the pitch and diameter cast into the exit end of the prop.

 

[Faztbullet]

Need to pull it off anyway as incorrect prop washer.

 

[merc850]

Need to pull it off anyway as incorrect prop washer.

It looks to me like the exhaust gases will exit around the blades instead of thru the hub.

 

[dingbat]

It looks to me like the exhaust gases will exit around the blades instead of thru the hub.

The prop is “ported”. Supposed to do that

If it’s like the one I ran on my last boat, the part number is on the hub, under the prop washer and nut.

 

[Lt1z350]

Thanks for reply’s I’ll pull it and as said grease it all up and check. Lower until oil was not the best so sure pre opus owner didn’t take care of things like that which can bite me later if need to swap it.

 

[Lt1z350]

So turns out it was decent and had grease but cleaned it all up and the prop does have the info on the back side of the hub. It’s a 24 pitch prop so I assume that’s decent for a 4 blade and a strong 150. I have been told this is the highest hp of the 150s being a late 89 xr4 2.4 ltr. So hopefully the prop is a good match as pricing them it’s even hard to find some new ones that don’t show out of stock.

 

[Sea Rider]

Without knowing the current number of passengers that were on board, max wot rpm achieved on flat calm water cond to compare it against the min-max wot rpm range factory stated for said motor won't know if current prop powers nicely and efficiently that combo at which wot rpm and true speed which it's a must know before going blindly to any other 3 blade prop...

Happy Boating​