Bad hub?

[LawsonRacing]

Ok I've got a 1989 evinrude110 on a 1989 arrow glass bass boat. WOT throttle is right at 5500rpms with a speed of about 30mph. I feel the boat just run faster. Prop is a 3blade 13"x19P. The weird thing it does too is on long runs (5+ mins or so) the boat will slowly start losing speed but not rpms. If I slow down and come off plane and then hammer back down, I'll be right back to 30mph like normal.....for a few minutes. Now this prop is severely jacked up, 1 blade is broken on the last half inch and the other 2 are very dinged up. I know that's hurting performance but it shouldn't cause it to slow the boat down I wouldn't think.
So I guessing the hub is letting the prop slip after a few minutes. But mainly I'm also asking if when I get a new prop, should I get the same one or change the pitch up?? I'm more used to a 60mph boat so this 30mph is killing me lol I know I won't get 60mph out of this thing but I feel it should run 40-45mph no problem. Thanks

 

[Maclin]

You need good numbers from a working prop in good shape before any meaningful assessment can be made. I would get a good 3blade 19p on it and see what happens next.

 

[briangcc]

To do that kind of damage to a prop someone smacked something fairly darn hard. My suggestion would be to pull the boat out and check the prop shaft to make sure you don't have a wobble. If you do, and I suspect you might, I'd address that first and then look at a prop.

I definitely wouldn't run the boat as is as your prop is out of balance so you will start causing other issues in your lower unit.


**Working from the following....my cousin on his 20' Searay was going above idle under a bridge, supposedly in 6' of water and broke off a good 2" chunk of his SS prop, bent over two more blades on his prop, took a good 2-3" out of his skeg on the Alpha outdrive, and bent the prop shaft. You could spin it by hand and see the wobble.

 

[LawsonRacing]

I've already checked that actually as it was damaged from I got my hands on the boat. Shaft doesn't wobble and there's zero vibration from the motor which honestly doesn't make sense as it has to be out of balance with a piece missing. I'm just trying to avoid buying a new prop only to need to buy another new prop.
Also something I forgot to add, it seems like there no speed increase from 5/8-WOT. Rpms increase but speed doesn't seem too. I figured it had something to do with the damaged prop. I'm still mostly confused on why it would run for a few minutes then slowly drop speed unless the damaged prop is taking that long to cavitate to the point of losing grip. I know I need a new prop and don't plan on running it again until ones on it. Just looking for some knowledge on why it might be doing what it's doing

 

[WesNewell]

Which model do you have? They range in weight from 850# to ~1300#. Hard to make a recommendation without knowing something about the boat you have, but 30 mph on even the heaviest one is way under what you should be getting with a 110hp engine. At minimum you should see 40 mph. prop should range from 19-21p depending the boat weight. I can squeeze ~40 mph out of my 1000# boat with a 60hp engine and 14p prop. Took changing engine height and props from original max 31 mph with 12p prop. to get to an under 6% slip, Just changing from 12p to 14p prop bought speed to 35 mph max without porpoising with a max speed of ~40 mph with a lot of porpoising. Raising engine 1.5" and lowering trim gave me a smooth ride at 38 mph and 40 mph with just a little porpoising.
A;so need to know the gear ratio of your engine.

 

[LawsonRacing]

Best I can tell is it's a 17ft Freedom One fish/ski with weight of 950lbs. No website says that Arrow Glass made boats in 89. They skip from 87 straight to 90 but my title says 1989 lol. Boat and motor are both 89 and from what I can tell they've been together the entire time. Motors never been moved up or down on trans. No clue on the gear ratio just know it's a 89 Evinrude V4 110hp crossflow motor.
The prop that's currently on it is a 13x19P. It comes out of the water pretty good just wondering if I'd hurt it too much by jumping up to a 21P to see about getting more speed out of it. Like I said I know it needs a new prop, my main question is would a damaged prop make it slowly start losing mph on long runs.

 

[WesNewell]

Looks like that engine has a 2.0gr, but 30 mph at 5500 rpm doesn't add up. Should be closer to 45mph. Have you checked the hub to see if it's slipping?. First thing I'd do is check the engine mount height before changing prop pitch. If it's mounted too low it could cost you 10-20% in top speed with everything else working perfectly. A 21p prop sounds reasonable to me. IIRC I had a 23p on my old `83 Kingfisher 15V with a 115hp rude. It weighed 750# and would hit 60 mph.

 

[LawsonRacing]

I haven't checked motor height yet. Thevpaint hasn't been scraped off so I don't think motors ever been moved from the dealer. Doesn't mean it wasn't set wrong to begin with tho. Think I may just order a 21P instead of the 19P that's one it now. Like I said boat comes out of the water great, just no speed. I'd sacrifice a little of that for more speed so I don't end up just wanting another prop immediately