newbie question 48 78120 A40 19P

[willis72]

Ok so first off im extremely new to boats like i just boat my first one today, im 50 years old and have to eat my pride by saying im a newbie lol so what i have is a 1991 starcraft 171 fs with the 3.0 mercruiser. the prop is beat all to crap and looks like its been filed to death and still has a chainsaw blade look to it. im not having to good of luck trying to find a replacement prop so here i am looking for some guidance. the number on the prop is 48 78120 A40 19P. i know the 19p stands for what pitch it is but thats all i know. can some one steer me in the right direction on the rest of the number and what they meen? and a possible replacement?

 

[jimmbo]

Welcome to iboats

https://boatpropellers.iboats.com/Mercruiser-Sterndrive-Propellers/?pitch=19.00&chart=77&engine_id=437&cart_id=595579299

 

[racerone]

Well 48 is a number to designate that part # is for a prop.----Just like 47 is for a water pump impeller.-----Then you have the part # ----Then A40 designates various minor design changes or production run of this propeller.

 

[Chris1956]

Sounds like a standard Mercury prop. A prop for that sterndrive should be easy to find, as they are the most popular.

Search for a prop wizard. Input outdrive gear ratio, boat length/weight and RPM and see what prop and pitch it suggests.

 

[briangcc]

Looks aluminum. That could be repaired by a prop shop. They may even have new/gently used ones you could try to see if performance is any better.

Just another option.

 

[Bondo]

Ok so first off im extremely new to boats like i just boat my first one today, im 50 years old and have to eat my pride by saying im a newbie lol so what i have is a 1991 starcraft 171 fs with the 3.0 mercruiser. the prop is beat all to crap and looks like its been filed to death and still has a chainsaw blade look to it. im not having to good of luck trying to find a replacement prop so here i am looking for some guidance. the number on the prop is 48 78120 A40 19P. i know the 19p stands for what pitch it is but thats all i know. can some one steer me in the right direction on the rest of the number and what they meen? and a possible replacement?

Ayuh,..... Welcome Aboard,.... Have ya splashed it yet,..??

If not, do so, to see if it likes the 19" pitch,..... ya should see 4600/ 4800 rpms, light load, properly trimmed,....
If ya do, go buy another 19" pitch Merc prop for it, 'n keep the beat up one for an emergency spare,....

 

[willis72]

Ayuh,..... Welcome Aboard,.... Have ya splashed it yet,..??

If not, do so, to see if it likes the 19" pitch,..... ya should see 4600/ 4800 rpms, light load, properly trimmed,....
If ya do, go buy another 19" pitch Merc prop for it, 'n keep the beat up one for an emergency spare,....

hoping to get her wet this weekend. as far as the stock prop ill keep it for a spare but had my local marina guy order a new one this morning. he told me there wasnt a stock merc prop in a 19 available in his system that scans the U.S. to find one. so his tech guy said he could put a prop made for a honda that a 14.5" 19 pitch the only difference was the thrust washer and supposedly the hub will work. idk it cost me 218 bucks so if it dont work idk what ill do.

 

[Yegboats]

Well 48 is a number to designate that part # is for a prop.----Just like 47 is for a water pump impeller.-----Then you have the part # ----Then A40 designates various minor design changes or production run of this propeller.

A40 was for the props for the pressed on hubs the A45 hubless props came out around 1996ish. Seems like i read that somewhere I think in a 1997 Merc prop guide.

If they're selling you a turningpoint prop for your 3.0 Merc. make sure it doesnt hit the trim tab anode. Its a little fin above the prop. Youll need a mercury hub Honda hub wont work.
Keep your old prop in the boat for emergency spare. Keep the crown washer with it new props wont utilize those.

 

[willis72]

A40 was for the props for the pressed on hubs the A45 hubless props came out around 1996ish. Seems like i read that somewhere I think in a 1997 Merc prop guide.

If they're selling you a turningpoint prop for your 3.0 Merc. make sure it doesnt hit the trim tab anode. Its a little fin above the prop. Youll need a mercury hub Honda hub wont work.
Keep your old prop in the boat for emergency spare. Keep the crown washer with it new props wont utilize those.

pretty sure this is what their selling me by the description on the reciept. exept mine will be 14.5"s https://www.boats.net/product/previ...YDP3XS995n0MzNP-Baw1bscpuV2JBn-IaAvB3EALw_wcB

 

[Yegboats]

pretty sure this is what their selling me by the description on the reciept. exept mine will be 14.5"s https://www.boats.net/product/previ...YDP3XS995n0MzNP-Baw1bscpuV2JBn-IaAvB3EALw_wcB

1511-145-19 is 14.5" x 19" I did not know 2012 and newer large gearcase Hondas are 15 spline too.

 

[willis72]

1511-145-19 is 14.5" x 19" I did not know 2012 and newer large gearcase Hondas are 15 spline too.

it might not be that exact one, im just going by some numbers i have on the reciept

 

[Chris1956]

So your boat guy couldn't find a 19" pitch prop for an alpha I drive? Not only is your outdrive one of the most popular, A 19" pitch prop to fit is one of the most popular.

I would expect Mercury as well as Michigan Wheel to have them. Solas and Turning point will also have them.

Just so you know, your outdrive takes the same prop family as all the Alpha ODs, all Merc V6 outboards, V6 Evinrude/Johnson OBs and probably lots of others.

Get a new boat guy.