[cliff717]

as the title says i just purchaced a 1997 shabah z242 it has a 454 and a alpha1 drive. and i need prop advice. the guy before me put a new prop on it and i think it is way wrong. the current prop is a alluminum 21-12 and it just spins like crazy on take off and takes like 30 seconds to get up to plane. and with 8 people on board it still spins 4600 rpm at wot. now there was also another ss prop that was given with the boat but it is dinged up a bit. it has 4813702 21p on it and it and it looks way bigger.
so please give me a place to start.
and please tell me this boat should perform better than this.
any advice would be great
thanks
cliff

[mikeyt]

We can try. I'm assuming that the 21 is the pitch & the 12 is the diameter in inches. If so, that is a very small diameter prop for that engine. I believe your WOT rpm range is 4800-5200 for the 454 so if you are turning 4600 then you can afford to drop the pitch by a couple of inches. This would mean you could look for a 19" 3 blade or an 18" 4 blade which would get you to approx 5100-5200 rpm. Either of those props will be in the 14.5 - 15.25" diameter range.

Here's a link to iboats.com propeller choices for your engine / outdrive combo which will give you an idea of what is available & the co$t.

[Phlorida]

Funny - the previous owner seems to have left you props on both ends of the spectrum. Based on Mikey's response the SS prop is too much prop.

[indykoch]

Just how much is "dinged up a bit"? Depending on how bad, you may want to try putting that one on and getting some numbers with minimal people on board.
I can't imagine a big block using a 19" pitch, but it also depends on how many people you normally have, what activities you do, and what performance you want (holeshot, top end, or all around).
The 12" diameter is definitely not right for that boat, but I'm thinking the 21" pitch is.
...and yes, your boat should definitely perform better than that!

[mikeyt]

Originally Posted by indykoch

Just how much is "dinged up a bit"? Depending on how bad, you may want to try putting that one on and getting some numbers with minimal people on board.
!

Probably not a bad idea. I'm not comfortable with dropping the pitch either until Cliff gets a better handle on his performance numbers with a 21" although when i ran his boat thru the prop selector it came up with a 19" pitch based on size/weight. Its possible that the tiny diameter of the aluminum prop is affecting the rpms. Possibly a local marina / prop shop has a good 21" prop you can try out if your SS one is too far gone.

[cliff717]

awesome guys thanks for the info; i may try to straighten out my ss and try it. it is not too bad just a couple of dings on each blade. is there any good places to send it too to get it re-done?

[mikeyt]

I'm guessing by your boating area (Rosseau) that you are here in Ontario. I've dealt with Kings Propellors on Honey Harbour Road near Port Severn and they do a good job.

[cliff717]

yeah i live in dunnville (1/2 hour south of hamilton) but we do have a cottage in rosseau

[mikeyt]

There must be someone down in the Dunnville - Welland - Port Colborne area that does prop repairs. Most marine shops / marinas will refer you to someone they use.

[cliff717]

ok so i banged out most of the small dents so that i can try the prop before i send it in to get it fixed. i am going to try it out tomorow night if all goes well.
thanksfor all the feedback