What is OEM prop 99 Larsen 186sei stern

[ME_man]

I’m new to boats.. I bought a well used 1999 Larsen 186sei stern drive with the Merc 3.0 Alpha One gen 2..
the boat came with a 4 blade Turning point Hustler 14 x19... my question is: What was the stock size for this boat? I suspect this prop is a replacement.
Also if anyone has any feedback regarding my current turning point prop -that would be nice too.
I’m working on getting the engine running right so I’m not sure how well the current prop works.
I’m planning to use the boat for skiing and tubing mostly.

 

[porscheguy]

The “stock” prop is whatever the dealer slapped on it at the time of delivery. 19, 21, and 23 are probably the three most common sizes. If you’re planning to do watersports a 4 blade 19 is probably your best bet. At the most you could do a 21 for towing (and that’s a maybe).

 

[ME_man]

The “stock” prop is whatever the dealer slapped on it at the time of delivery. 19, 21, and 23 are probably the three most common sizes. If you’re planning to do watersports a 4 blade 19 is probably your best bet. At the most you could do a 21 for towing (and that’s a maybe).

Great.. sounds like I’m all set then. I appreciate your response.

 

[Bondo]

I’m working on getting the engine running right so I’m not sure how well the current prop works.

Ayuh,..... When the motor is runnin', Perfect,.....
The perfect prop will allow the motor to spin 4700/ 4800 rpms at Wot, light load, trimmed up abit,....

Less than 4200/ 4400 rpms is luggin' the motor, which leads to burnt up pistons,.....

 

[ME_man]

Ayuh,..... When the motor is runnin', Perfect,.....
The perfect prop will allow the motor to spin 4700/ 4800 rpms at Wot, light load, trimmed up abit,....

Less than 4200/ 4400 rpms is luggin' the motor, which leads to burnt up pistons,.....

Ayup.. she’s runnin.. just not right.
Thank you. I’ll take that into consideration..I’d really hate to ruin her now.

 

[ME_man]

I’m not sure this is prop related or not.. but.. this boat doesn’t have a trim fin anode.. should it? It has a flat anode there. The steering did seem a little wonky..took a lot of work to keep it in a straight line.. but maybe because I wasn’t up on plane when I tried it.

 

[jimmbo]

With I/Os, the prop was probably chosen by the boat manufacturer, not the dealer. You might try contacting Larsen, they might have some history/knowledge of what they shipped the boats out with. HIN would help.

Your engine WOT rpm range is either; 4200 - 4600 rpm, or 4400 - 4800 rpm. I don't remember what year the speed changed.
Propping for 4600(middle of one spec, upper end of the other) if you don't know what the range is. Is there a Decal/Sticker on the engine or flame arrestor with that info?

What kind of skiing are you planning on doing? At 130 hp out of a stern drive, it capability will comparable to about a 80 - 85 hp outboard on the same boat, just slightly slower acceleration

I/Os, for some reason are a little Squirrelly when operated at low speeds

If you have power assisted steering, there won't be a trim tab behind the prop

 

[QBhoy]

Hi
general such a set up would come with a 19 or 21” black max 3 blade if a mercruiser. The 19” would be at the lower end and if heavy or at altitude.
As for the anode. If you have power steering then you would generally have a flat anode without a fin. If not, you would have one with a fin.

 

[ME_man]

Thanks the all the input guys.. much appreciated.
I didn’t realize the dealer chooses a prop. I figured they came with a standard factory prop. I’m going to go with the one on the boat.. for now. I may swap for a stainless down the road as I understand they put more power to the water.

 

[jimmbo]

I/Os usually came with a prop from the Factory, chosen by the boat manufacturer.

 

[porscheguy]

I/Os usually came with a prop from the Factory, chosen by the boat manufacturer.

This is correct. They come with a prop from the factory. But they’re not installed from the factory, nor are the installed on the lot because things like props are known to grow legs and walk away, especially if a lot of crackheads are nearby. So they get tossed into the storeroom for new boat stuff at the dealership. Maybe the dealer will mark the prop to go with a specific boat, but I wouldn’t put that much faith in them. Considering how lazy most in the industry are, I’d bet money they install whatever prop their hand falls on first when they go into the store room to grab all the new boat gear when a sale is made. I can’t confirm this, and of course no one will admit.

 

[jimmbo]

This is correct. They come with a prop from the factory. But they’re not installed from the factory, nor are the installed on the lot because things like props are known to grow legs and walk away, especially if a lot of crackheads are nearby. So they get tossed into the storeroom for new boat stuff at the dealership. Maybe the dealer will mark the prop to go with a specific boat, but I wouldn’t put that much faith in them. Considering how lazy most in the industry are, I’d bet money they install whatever prop their hand falls on first when they go into the store room to grab all the new boat gear when a sale is made. I can’t confirm this, and of course no one will admit.

I can see that happening.
From experience, I know the dealer I bought my boat from kept a pretty good track of what Outdrive and what Prop went with which boat, by writing the HIN # on each carton, and also the prop Pitch on the hull and outdrive's carton