73 grady/inline 6 prop selection

[cmorr176]

can anyone tell me what the correct prop or factory prop would be for a 73 grady white nassau running a mercruiser inline 6/250 /165 hp. motor would be.it came with a 14x16 prop which needs replacing. is this the right one? thanks.also is it possible to pull the motor( it is shot) without pulling the outdrive and transom seal. i have a nice running replacement ready to go and do not want to pull the new transom seal that i replaced last year.

 

[Reel Poor]

Re: 73 grady/inline 6 prop selection

To pull the engine you do have to remove the drive. Removing the drive will not disturb the transom shield seal. When you install the new engine be sure to check engine alignment or you'll be pulling the engine again to replace the coupler.

As for the prop it's really hard to say. We need to know the WOT rpm's. I would think that a 16 or 17 would be a good starting point.

 

[Bondo]

Re: 73 grady/inline 6 prop selection

The Outdrive Has to be Pulled, Before the motor can be Removed......

The Transom Assembley, both Inner,+ Outer do Not need to be disturbed.......

As for the Prop,.......

Without a Baseline of the motors capability at WOT,......

I guess you'd better Start out with what Was on it.......

 

[DukesFin]

Re: 73 grady/inline 6 prop selection

Okay, on my '74 model GW 212 Chesapeke, I originally had a 15 pitch prop. Got to over 35mph at just over 4Krpm.

Moved to a 19p prop and could only get her to around 33-34mph and the max rpm I could get was around 3200.

I've just put a 16p prop on and havent' tested it yet, but I will week after next.

 

[Bondo]

Re: 73 grady/inline 6 prop selection

I originally had a 15 pitch prop. Got to over 35mph at just over 4Krpm.

Sounds like you're goin' the Wrong Way with that 16"er.......

WOT is 4200/ 4400 on those motors........

For that Matter,....
Dropping to the next Lower Gearset in the drive would get you to where there's More of a Selection of Props that'll Fit...........

 

[ziggy]

Re: 73 grady/inline 6 prop selection

the mercruiser service manual has a table in it regaurding best estimated pitch chart. but need to know the leangth of the boat to give ya what it says. i'm runnin a 19 on mine. and the chart is right for me. not to say it will for you as ea. boat is diffent. but it's a baseline start.....what's the leagth of yer gw nassau?

WOT is 4200/ 4400 on those motors........

my oem service manual calls for wot of 3900-4300? for both my 75 and 72 L6......least theses are the numbers i've been usein.....

 

[FreeBeeTony]

Re: 73 grady/inline 6 prop selection

I had a '78 Grady Gulfstream with the IL6..........

Had a 15" prop and would just make 3800 RPM's....
Think it was due to the weight of the boat.

 

[DukesFin]

Re: 73 grady/inline 6 prop selection

I originally had a 15 pitch prop. Got to over 35mph at just over 4Krpm.

Sounds like you're goin' the Wrong Way with that 16"er.......

WOT is 4200/ 4400 on those motors........

For that Matter,....
Dropping to the next Lower Gearset in the drive would get you to where there's More of a Selection of Props that'll Fit...........

I got the 16p prop for next to nothing and it's sure going to be a LOT better than the 19 that I've been running on her! I hope to move back down to a 15 or possibly a 14, but for now, the 16 will have to do.