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nishjg

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"I was out crusing the bay, an

"I was out crusing the bay, and found some rocks at cruising speed. I just came straight back to the dock to inspect the damage. It had a slight vibration while on my way back. I found the tip of the skeg was missing about 1.5 inches back from the prop and almost to within 1.5 inches from the gear case. So I am missing about a quarter of it. The only damage the prop had was a 1/4 inch bend on the one blade edge. I have a 1985 merc 140. It says 3.0 on the outdrive. I suspect that the vibration is from the prop, but my question is: Should I just take it out and inspect? What should I be checking? It didn't seem to be leaking any lower end oil or anything."
 
your depth finder.
You may ha

your depth finder.
You may have gotton off lucky with just 1 blade.
Replace the prop and let us know.Unless the shaft is bent you should be fine.
 
This is one of the reasons I h

This is one of the reasons I have allways used a aluminum prop. Better to replace the prop vs a prop shaft.

Thoose damn ROCK BASS.......
 
"Yes, my depth finder goes all

"Yes, my depth finder goes all erradic while cruising..older model and probably coming out of the water or something. O.k. Thanks guys, I will let you know what I find."
 
"One more question, If I have

"One more question, If I have to change that prop, I would like to put a four blade on it. For the simple reason that with four adults loaded, it has a hard time getting to plane. The boat is only 16.5'. I don't know what's on it right now, other then 3 blade. I assume it's a stock pitch, if there is one."
 
The prop shaft is critical. I

The prop shaft is critical. I use two depth finders. One is a comb. fish/depth w/the bottom alarm set at 6'. The other is a digital Faria gauge w/the alarm set at 5'. It uses a thru hull transducer w/a base ring glued to the hull w/silicone glue and is filled w/mineral oil and the transducer mounted on top. It provides continuous bottom readings at any speed or depth.
 
There is a bolt on replacement

There is a bolt on replacement skeg that looks good and is cheap compared to removing and disassembly of the lower unit. Slip it over what is left of your skeg and bolt it on. Around $100.00 8 years ago.
Put a dial indicator on the prop shaft first. Your insurance will cover underwater damage. If the shaft is out of specs the unit has to be serviced. Same thing happened to me. State Farm shelled out $2500.00
 
You might be able to have the

You might be able to have the skeg welded on at the same shop that fixes your prop. Not sure about the cost but I had a prop guy tell me they can do minor repairs to skegs.

Hey Kghost I use a SS prop with a sacrificial hub. I'm hoping it works better than the alum prop as far as taking the hit. I keep an extra hub and prop on board. Just in case.
 
"I know the prop pitch and siz

"I know the prop pitch and size is almost done to death on this site but.. I found out I have a 21p 14 diameter prop. the trim tab was broken off because of this big prop. It was on there when I bought it. I think this is too much prop, at the boat is a 1985 Doral 16.5 foot with a merc 140 in it. Any suggestions or help?"
 
Well my experience is that sta

Well my experience is that stainless steel does not like to bend or break.

I am not sure about the "sacrificial" hubs and if they will actually sacrifice themselves before damage.

Maybe someone else can chime in......

I have always used aluminum as my boat sits rather deep in the water and the local lake I use it on I have hit any and all that can be hit at one time or another.

All I have ever replaced is props...........
 
"Yes, I am going to replace it

"Yes, I am going to replace it with aluminum. I am on Georgian Bay in Ontario Canada, and there are a quite a few shoals around here. I would say around 4000rpm WOT on the dash guage. It does take some time to plane out with 4 adults in it, and the nose points up pretty high."
 
"The WOT for your engine is 42

"The WOT for your engine is 4200 - 4600 RPMs. I'm betting the 4 adults are the problem w/the prop you have. Drop down in pitch to a used, repaired or good condition 17P. If that brings the WOT to 4400 RPMs then buy a 4 blade 16P. That will allow the boat to plane quickly. Keep the 17P as a spare."
 
"Ok. Thanks for the help Guy a

"Ok. Thanks for the help Guy and everyone else, greatly appreciated!! I will try that out. My prop shaft is ok as well for an update."
 
Kghost FYI the sac hubs are ma

Kghost FYI the sac hubs are made of nylon and definitely will spin out when the prop hits an object. In the San Juan islands there are plenty of shoals that come up from the deep and during low tide are visible but during high lie just under the surface. You can be in 200 feet of water and all of sudden there are surface rocks. Most are marked and well known but there is always someone every weekend that hits one. But the sac hubs are well tested around here and most people use them with confidence. I trust them more than aluminum although I keep my OEM alum on board as a spare. I also keep an extra nylon hub as well.
 
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