[Stutterin_nate]

The prop that is on the boat now is a 17 pitch (there is a 17 stamped on it i don't know for sure) Stainless steel 5 blade. the engine is a 180 hp 4.3LX. Is this a good one or something i need to look into replacing?? Thanks!!

[mikeyt]

What kind of performance are you getting? Top speed (via GPS if possible)? RPM's at top speed? What do you use the boat for mostly; cruising or towing tubes/skiiers/wakeboarders??

[Stutterin_nate]

I havn't got the boat in the water yet. i bought it a few weeks ago and hopefully today after i redo the carb i will get er on the water and find out.

[Stutterin_nate]

i am getting around 4900 rpm's WOT and around 40 mph without a gps to verify. mainly we will be cruising and pulling tubes. i asked because a couple of people said 5 blades is too much. i have a 3 blade ss prop on a bad outdrive but i can't see nothing stamped on it to know pitch....

thanks!!

[SEMIJim]

Originally Posted by Stutterin_nate

i am getting around 4900 rpm's WOT and around 40 mph without a gps to verify.

On our 1994 182 Barchetta, with a 4.3L MerCruiser V6, 4bbl carb, Alpha 1 drive with 14x23 aluminum 3-blade prop I get 45MPH (by the speedo) at 4800 RPM WOT.

Originally Posted by Stutterin_nate

i asked because a couple of people said 5 blades is too much.

Too much what?

Mainly a five-blade is going to give you better hole shot with somewhat lower top end (probably), for the same size and pitch prop.

With a tube you're not so much worried about hole shot, like you are with skiers. Sounds like your current prop is about right. You could try going down an inch in pitch, which may improve everything, all around, or not.

The science and engineering can only predict gross effects. I.e.: More pitch leads to worse hole shot, but more top end and better fuel efficiency. Less pitch the opposite. But, from what others reported here, our boat shouldn't do well on hole shot with a 23 pitch prop, but she does. Even with four people in the boat, she pops up on plane like a cork. Has a decent top end and gets pretty good fuel economy. We lucked-out

Point is: Prop selection can be a hit or miss proposition.

Jim

[Stutterin_nate]

thanks!!

[mikeyt]

Jim's boat is a rarity that can run a 23" prop and i'm a little bit envious. Dont expect your boat to do so too. Your prop will be stamped at the front on the inside of the hub. I'm guessing (as Jim did) that you are likely using a prop that will work but its clear the boat isn't performing like it should. I suspect you could run a 19" 3 blade and get slightly lower (200 or so) rpms and a little more speed at top end without losing much low end grunt. The drop from 5 blades to 3 blades will offset some of the rpm drop you normally get when you increase your pitch by 2" (which would be about 400rpm).