Prop for OLD OMC... What pitch?

[DukesFin]

I've got a '74 Grady White 212 Chesapeake. Running it is a GM L6 250cid (165hp) and an OMC Stringer Elec. Shift outdrive...

Right now, I've got a 19pitch prop on it and while on the water, I am only able to get my RPM up to 3000 and speed (on the GPS) is 33.4mph.

I know my engine can turn faster @ WOT as it did before I put this used lower unit on (and the prop I am running came with the lower unit). My old prop is so old that I can't read the pitch on it, but apparently, the pitch was not as high as 19.

The speed I can get to right now is fine, but I use my boat in the Gulf of Mexico a lot and want to be sure I can run from a storm quickly if I need to.

Any help is GREATLY appreciated!

 

[Crownie2]

Re: Prop for OLD OMC... What pitch?

It sounds like the gear ratio in the lower unit is different than your old one.

I know that engine does not to rev high but I don't have a figure for you.

Think you could find a15" and try that??

Bob

 

[FreeBeeTony]

Re: Prop for OLD OMC... What pitch?

I think the WOT on that engine is 3800-4200RPM.

 

[DukesFin]

Re: Prop for OLD OMC... What pitch?

Gear ratio on Stringers is in the upper unit and I'm using my "old" one. (Confirmed this)...

It has to be a pitch issue. I've gotten a lot of responses from the Grady White forum.

The only problem is now, do you know how hard it is to find an old OMC prop locally -- that someone will let me "test" with????

Aaaaarrrrggghhh! 8)

It's all good though... At least we're on the water in the lake for now!