Props
 

For those considering...

I have a '97 Shabah Z210, 250hp Alpha 1, that struggled a bit to plane out. I put a Mercury High Five stainless prop on it, with the same pitch as my 3-blade, and my boat jumps right out of the water and haven't noticed any loss of speed at WOT.

Prior to changing the prop I considered Hydro-foil. I'm glad I went the prop route instead.

The best $300 I have spent (was patient and waited for one to show up on Craig's List).

That's great! Although I've never heard of a 5 blade keeping the same top end as the 3 blade of the same pitch. I'm glad it worked out for you! Are the diameters of the 2 props the same?

My first suggestion would have been Smart Tabs. I'm a firm believer in those things! Better hole shot, better ride (seems to "cut" through the waves MUCH better), less low speed wonder, etc.

But if this worked as well... great! Thanks for sharing.

I currently have a SS 14.5 x 19p on my 180 shabah with 190hp 4.3. I have a hydofoil as well, what prop should I get to add top end and still maintane hole shot? My boat planes super fast in just a few seconds but I want a little more top end. I was thinking of a 4 blade 20 pitch to maintane hole shot but add few MPH to the top, would that work?

Increasing your pitch to 21 will increase your top speed and lower your top end rpm by about 200-300. For example, if you are hitting 47-48 mph at 5000rpm right now a change to a 21 pitch prop should increase your top end to 50-51 mph & drop your rpms to around 4700 - 4800 at top speed. A 4 blade, 20p SS prop will likely give you a top speed of 49 - 50mph and have your rpms at 4800 which will give you a little more top end without sacrificing any of the grunt and it should give you a little more mid range pull. The thing is to keep your rpm's within the recommended range for your motor. The 4.3 has a range of 4400 to 4800 rpms.

Understand though this doesnt apply 'right to the tee'. Each boat (even though they may be the same size / motor) can be just a little different but the above will be a close guideline. I have the same combo as you and have installed a 4 blade - 20p SS prop & this is what i am expecting.

As for the hydrofoil, i'm with Indykoch. Smart tabs are better.

I will see what kind of MPH I get this weekend. Last week with 4 people and full tank I was only getting about 40mph and 4300 RPM, but when I took the boat out of the water I noticed that the prop was damaged(damn driftwood). It was also the first time the speedo was working(clogged hole). I pick up the repaired prop tomorrow and it will be just me and wife this weekend and only 1/2 tank. If I am not happy with the performance this go round I will put the prop on craigs list and upgrade.

40 mph & 4300 rpm is quite low for the combo you have. Mine had a 3 blade aluminum 21p prop and would consistently hit 50-51mph at 4850 rpm. What i lacked was some low end & mid range grunt which the 4 blade - 20p SS prop should provide in spades.

You would be best to measure your speed with a GPS though. Boat speedos are notorious for being just 'a lttle off' although if your prop is damaged to a moderate degree it will affect your performance.

I don't have smart tabs installed on my boat, but I have been around here long enough and on another boating webpages to know that Smart Tabs are the way to go.

Bpfirrman, dump the hydrofoil, install I think the 60lb vs 80lb actuators for the smart tabs and enjoy them. :)

I personally think those hydrofoils look dorky on a sterndrive. :D


btw - my boat goes 33-35 speedo mph... 14p / 3 blade prop. :)

a 14 pitch prop ?? are you sure ?? I would have thought you would run a 17p or 19p. No wonder ya only do 33-35mph with that 3.0

180 diablo my old boat was a 18ft cobia bow rider 1988 3.0 OMC IO and I had a 17 pitch 3 blade ss prop on it and that thing would do 45mph and still jump right out of the water on take off you should honestly think of upgrading to a 17p propI think you would like it better:)

Sorry my bad.
When I typed that up the other day, all I could remember was the 14.

14.25 hub x 19P - 3blade. :rolleyes:

Hi 18-0diablo,

That's more like it, geez, a 13P prop would probibly blow your engine at WOT! :eek_animated:

Anyway, I think your speedo is off a bit.... my old 18.5' Sea Ray w/3.0 & 19P aluminum prop hit 43-45 at WOT and 4800RPMs. I propped it down to 17P for a better hole shot while slalom skiing but I had to watch the rpms cause the motor revved up quicker!.

WetWilly

hmmm.. i agree with Willy. Your speedo cant be right. You should be able to run in the low 40's at WOT and optimum cruise in the 33-35mph range.

btw....did you see the '93 Diablo 180 on e-bay ?

So I just got back from my first trip out with the repaired prop and something is not right.
First run at WOT and I was only getting 4300 RPM with my 14.5x19p prop. Top speed on the boat speedo was only 43. What concerns me was there was more than usual vibration,dashboard was really vibrating. Did not push it too hard the rest of the day. My last run at WOT I was barely able to get 4000 RPM. Do you think they did not prepair the prop correctly? What else could it be? First time I took the boat out I was getting 4800 RPM at WOT.

I will check on the balancing. My prop does not have a hub kit, it bolts directly to the prop shaft(Attwood Ballistic). I did not notice any damage to the propshaft when I took the prop off, but I am no expert either.

Well, I will be GPS speed testing my boat this summer to see what it does. I also will have a new prop installed this spring.


http://cgi.ebay.com/ebaymotors/1993-...spagenameZWDVW

That one. :) Looks nice.

However im curious about something... how did his seats come with "Mariah" stitched into the back portion? Maybe a change when mine was buildtand when his was built? Unless mine has been recovered of course. But to me it looks all factory colouring.

Also, whats up with his steering wheel? Is mine the normal one and that is a replacement?

Sorry, I didn't mean a Hub Kit, I ment the rubber coupler inside of the hub. Almost every prop I've seen has some kind of rubber coupling in the hub to prevent or reduce damage in the event of a prop strike by allowing the prop to slip on the hub.

I was going to suggest contacting Attwood to find out if your prop has a rubber coupler, but they sold the Ballistic Prop line to Michigan Wheel back in 98, but you can try:

Attwood Headquarters
1016 N. Monroe Street
Lowell, MI 49331
PH: 616 - 897 - 2290

[email protected]

I do know the Michigan Ballistic Props have a shock absorbing coupler in their hubs.

Michigan Wheel Corporation
Inboard & Outboard Propeller Division
1501 Buchanan Avenue SW
Grand Rapids, MI 49507
Phone: (616) 452-6941

[email protected]

I would still contact the shop that did your prop repairs and ask if you have a hub coupler and if they checked it. If you do have a hub and they didn't check it, find yourself another shop as this one isn't through!

WetWilly

I will take my prop off again and check, that may be what the problem is. Rather spend 50 on a rehubbing than a new prop.

It does appear that my prop has a hub insert in the prop. I could understand how that along with poor balancing would cause the vibrations. What concerns me now is the low RPM. If the hub was slipping I should be getting higher than normal RPM with less speed, correct?

The hubs rarely "slip", but rather "fail". You'd probably notice the hub being loose in the prop if it got to the slip/fail point. From the sounds of it, the hub is tight within the prop which makes me think the hub isn't the problem.

My other thought would be possibly a bent prop shaft. That would cause the vibration and maybe lack of RPM's as well. It's more difficult for the engine to turn the bent shaft at WOT. As badly as you damaged the prop and skeg, I'd certainly think this is a possibility.

Definitely check with the repair shop first though - make sure the prop was balanced when repaired.

I've got a 19P Mercury High Five Stainless on my 180se with the 4.3 and love it. It leaps out of the water and planes out in 3-4 seconds. I'm sure the speedo if off, but I can still reach an indicated 47mph with three people and some equipment. It's rare I can go WOT at our lake (too windy) so this prop works perfect.

I checked with the prop shop and they did balance it, they are the most reputable shop in town so I figured they had. They offered to take a look at it again but at this point I am suspecting it may be the propshaft itself. If you hit something hard enough to take a 2" chunk out of the skeg and the hub did not break loose like it is supposed to it may have done some damage elsewhere. Ahh the joys of boat ownership!

Your speedo wont be off by too much. At best you could expect 48-49 mph with that 19p prop but theres no question that the High 5 is a nice prop, particularly for watersports.

So I replaced my damaged prop and upgraded to a 21p SS prop this time. The shop I spoke to recommended replacing the prop and taking it out again before bringing it in to see what is causing the vibrations. Good news is that the boat ran smooth, no vibrations so I am to assume the prop shaft is fine. Not sure if I liked the 21p prop though. The shop, which sells Cobalts and is a ceritified Merc dealer, said that if I am hitting 4700-4800 with a 19p prop I should leave it alone(should have listened). I was only getting 4200rpm with the 21p and did not notice any improvement in top end. I am going to exchange it for another 19p and see what kind of performance I get. The other thing that my shop said to keep in mind is that I will not get the same performance as someone else on this board with the exact same boat and motor combo who is in another part of the country or another country altogether. The lakes in AZ that I frequent are between 1700 and 2500 ft in elevation, which can have a big impact on performance. Not to mention they are always busy and very choppy, unless you go out at 8am the lakes are very rough. What elevation are you guys at?

Glad to hear it was just the prop and not the shaft causing problems. IF you were maxxing out at 47-4800 rpm with the 19 pitch prop then i would agree. 4400 - 4800 is the recommended range for the 4.3 so 4200-4300 rpm with the 21 pitch prop is too low. Where i boat in southern Ontario is around 500-600 ft above sea level. There is no question elevation negatively affects performance, particularly at WOT. Since air gets thinner as altitude increases, the engine begins to starve for air (oxygen) and horsepower is lost resulting in a noticable reduction in power & rpm. Usually a pitch drop of 2 - 4" will resolve that issue allowing the engine to rev into it's correct range. It sounds like a 19 pitch - 3blade SS prop or possibly a 19 or 20 pitch 4 blade will give you optimum performance in your location. Prop selection isn't a perfected science as yet despite all the tools out there. A lot of it is educated guesswork, experience and 'try it & see'. :)

What happened with your top speed? You indicated 40mph earlier. You should be in the mid to upper 40's i would think. Again, the best way to measure it is with a GPS unit.

My top speed with the new prop was in the low 40's, the lake was REALLY rough though due to holiday weekend traffic. This weekend when I take it out with the new 19p I will bring a GPS and see what I am getting. If the RPM's are back up to 4700-4800 I imagine I will hit between 48-50. I think if I was out at a lake with an levation of around 400-800 ft I could probably go with a 21 and still muscle 4500-4600 RPM out of it, problem is the only lake in az with that elevation is almost 4hrs away so I will stick with what works best in the local lakes.

My boat sounds about the same as yours, Shalayne. Big Red is 1997 Z210 with Alpha and 5.7LX. What pitch was your original prop and the High Five? I run a 21" pitch Vengeance, which is 3-blade stainless, and also a 20" pitch, 4-blade aluminum prop. Both props get me out of the hole adequately; the 4-blade comes out a little quicker. I was considering a High-Five 21 pitch, believing that a 19 pitch would take too much off the top end. I am also considering the smart tabs. They sound fabulous. Please let us know.