Prop Dia - Maxum Boat Owners Club

donald · 05-10-2018, 06:14 PM

Does anyone know what is the largest prop that you can put on a Mercruiser A1G2. I am looking for diameter only.
Will a 15 inch dia. fit? I now have and I know that it will fit a 14.5 dia.
Thanks .
Don

mmwjr · 05-11-2018, 02:18 AM

I think it may take up to a 16 inch diameter but that’s almost scrapping paint, I would not exceed 15 inches.

donald · 05-11-2018, 03:11 AM

Thanks Mike.
I will check it next time at the boat.
Better to be sure than spend boat bucks on something that wont fit.
Just that I am unable to get there at the moment.
Thanks
Don

shrew · 05-14-2018, 02:13 PM

Props should be spaced from the hull or anti-ventilation plate 15% - 20% of prop diameter.

14.5 = 2.175 - 2.9 inchees
15 = 2.25 -3 inches

This is usually why the pitch and blade count is tweaked, but rarely size.

Measure the space you have now and calculate it out to see if you can swing a 15".

donald · 05-15-2018, 12:21 AM

Thanks shrew
I will do that the next time at the boat.
It seems to be hard to find a 14.5dia. X 15p.
I am running a 14.5dia. X 19p. now and can only get to about 3800 rpm.
So a 15p. should get near proper rpm.
Thanks.
Don

mmwjr · 05-15-2018, 01:40 AM

Quote:

Originally Posted by donald

Thanks shrew
I will do that the next time at the boat.
It seems to be hard to find a 14.5dia. X 15p.
I am running a 14.5dia. X 19p. now and can only get to about 3800 rpm.
So a 15p. should get near proper rpm.
Thanks.
Don

Don a 5.7 in that boat should have no problem achieving proper WOT with either a 17 or 19 pitch, must be all that retirement gold you’re carrying around.

When was the last time she was tuned up?

shrew · 05-15-2018, 02:00 PM

Quote:

Originally Posted by donald

Thanks shrew
I will do that the next time at the boat.
It seems to be hard to find a 14.5dia. X 15p.
I am running a 14.5dia. X 19p. now and can only get to about 3800 rpm.
So a 15p. should get near proper rpm.
Thanks.
Don

I see the dilemma. How about weight and weight distribution. 15p seems low. What does the Mercruiser prop calculator come up with?

donald · 05-15-2018, 06:19 PM

Mike
I think the problem is that all the iron in my blood has turned to lead in my ass.

shrew
The prop calculator states a 14.5dia. X 17p. I am never run it over 3000 rpm as it is, its just that at an idle it is to fast to troll, Wife likes to troll fish.
Just trying to keep her happy.
Thanks to both of you.
Don

mmwjr · 05-16-2018, 02:21 AM

Quote:

Originally Posted by donald

Mike
I think the problem is that all the iron in my blood has turned to lead in my ass.

shrew
The prop calculator states a 14.5dia. X 17p. I am never run it over 3000 rpm as it is, its just that at an idle it is to fast to troll, Wife likes to troll fish.
Just trying to keep her happy.
Thanks to both of you.
Don

Well unlike iron lead doesn’t rust.

donald · 05-16-2018, 02:23 AM

Well I made it to the boat today to measure, and I have 1 inch from tip of blade to anti ventilation plate.
I did measure the prop dia. and it is 7.25 inches from center of shaft to tip of one blade (14.5 inches dia.)
I can not find a 14.5 X 15p anywhere, so will go with a 14.5 X 17p.
By the way I have a 14.5 X 17p and I can reach 4400 to 4600 rpm, its just in very bad shape.
Thanks again.
Don

mmwjr · 05-16-2018, 02:27 AM

Quote:

Originally Posted by donald

Well I made it to the boat today to measure, and I have 1 inch from tip of blade to anti ventilation plate.
I did measure the prop dia. and it is 7.25 inches from center of shaft to tip of one blade (14.5 inches dia.)
I can not find a 14.5 X 15p anywhere, so will go with a 14.5 X 17p.
By the way I have a 14.5 X 17p and I can reach 4400 to 4600 rpm, its just in very bad shape.
Thanks again.
Don

Must be from that lead ass causing it to hit bottom.

shrew · 05-16-2018, 03:00 PM

Quote:

Originally Posted by donald

Well I made it to the boat today to measure, and I have 1 inch from tip of blade to anti ventilation plate.
I did measure the prop dia. and it is 7.25 inches from center of shaft to tip of one blade (14.5 inches dia.)
I can not find a 14.5 X 15p anywhere, so will go with a 14.5 X 17p.
By the way I have a 14.5 X 17p and I can reach 4400 to 4600 rpm, its just in very bad shape.
Thanks again.
Don

With an inch of clearance, you're not going to want to go to a 15" diameter prop. Getting 4400 -4600 is pretty good for the target range of 4400 - 4800. going down to a 15" Pitch will bring your max rpm range up to 4600 - 5000, which would be too high. Fully loaded will probably be fine, but you would need to be careful with light loads.

I'd consider buying a new 14.5 x 17. 14.5 x 17 x 4 might work for you.

donald · 05-16-2018, 04:01 PM

Good morning shew.
I am looking at a 14.5 X 17p 3 blade.
Found 1 on the internet but can't seem to get it to my shopping cart.
Going to try again this morning, if it wont work might try and call them to order.
Thanks again.
Don

donald · 05-16-2018, 04:04 PM

Good Morning Mike.
Yea I know I'm going have to work on that!
Too thin of water or too much iron!
Don

mmwjr · 05-16-2018, 04:58 PM

Quote:

Originally Posted by donald

Good Morning Mike.
Yea I know I'm going have to work on that!
Too thin of water or too much iron!
Don

I understand buddy, kind of got the same issue myself.