Props

WetWilly · 05-09-2008, 05:34 PM

Quote:

Originally Posted by 180diablo

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

14.25 hub x 19P - 3blade.

Hi 18-0diablo,

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

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

***mikeyt*** · 05-09-2008, 05:38 PM

Quote:

Originally Posted by 180diablo

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

14.25 hub x 19P - 3blade.

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 ?

bpfirrman · 05-11-2008, 03:34 AM

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.

WetWilly · 05-11-2008, 11:02 AM

Hi bpfirrman,

Contact the prop shop you had do the repair on you prop and ask:

1) What was involved in the repair of your prop (Any re-cupping, re-balancing, etc...)

2) Ask if they checked the hub for damage or signs of slippage or replaced it.

Hopefully they re-balanced your prop after they fixed the damage! That being the thought, I suspect possibly a hub issue, Typically hubs don't hold the same after a prop strike or two and if your's is now worn, it could cause your prop to slip lowering your performance and as the hub wears down further, can lead to wobble creating the excessive vibration your experiencing.

Let me know what you find out and good luck,
WetWilly

bpfirrman · 05-11-2008, 03:22 PM

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.

***180diablo*** · 05-11-2008, 06:58 PM

Quote:

Originally Posted by mikeyt

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 ?

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?

WetWilly · 05-11-2008, 11:20 PM

Quote:

Originally Posted by bpfirrman

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.

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

bpfirrman · 05-12-2008, 01:03 AM

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.

bpfirrman · 05-12-2008, 06:36 PM

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?

***indykoch*** · 05-12-2008, 06:55 PM

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.

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