Prop Question

[Tuna Man]

Both props on the 06 Yamaha 250 outboards that are on the Marlin I am about to purchase are Yamaha 15x19 Saltwater Series II. The inside of the hub on both props is rust colored and rough. The rest of the prop is covered with rust spots. My now eight year old SW Series I prop on my old boat looks much better.

My question is does anyone else have this problem with thier 'polished' stainless props? Any idea why this rust and perhaps pitting would occur? I am concerned it may be from cavitation or aerating the props. I guess it could also be from stray current from shore power? For the record the boat appears to have been in a slip most for the last year or so. The previous owner had the leading edge of the lower unit that touches the water when the motors are tilted up painted with a special paint that resits algae growth. Lastly the transom and motor bracket are fouled with some kind of green algae. I will find out how fouled the bottom is when I revisit with the surveyor.

 

[HDGWJOE]

Personally, I think Yamaha had, or still has, a quality control problem with the "grade" of stainless they use for their props (or their supplier does).
I had a 2003 282 with F225's and never had a problem with minimal care. They always looked great. Then I moved to a 2005 Marlin with F250's and my props looked like crap within a couple of weeks. I took the props off the boat and with some elbow grease and very fine brass wool(0000) and Flitz followed by a good buffing(with Flitz) they looked great the rest of the season. Now I do that every season before the boat goes in. When my boat is docked my F250's are slightly touching the water also. I paint that part with Trilux ablative paint and change my zincs religiously so I doubt my rust problem was electrolysis related. Electric current will follow the easiest path in the water which would be your aluminum lower unit.

I mentioned the "rust" problem to the Yamaha reps at the 2006 NY Boat Show and basically they blew me off.

 

[Tuna Man]

Joe,
Thank you for responding so quickly. I think you may be correct, and it is just not the best quality stainless/polishig job from the factory. Also, the fact that the boat has hardly been used in the last year may be contributing to the problem.

I guess I'll just have to put some elbow grease into it and see how it polishes up.

 

[HDGWJOE]

Good luck with the purchase Scott... you'll love the Marlin and the 19" props are the recommended props for that boat. Mine came with 17" and not too long after that Grady started recommending the 19" with the F250's. The other thing that nagged me when I bought my boat was whether the dealer put brand new props on my boat (which I paid for) or if he used demo's. Inside of one hub was rustier than the other but I didn't notice that until I was back at my marina 50mi away.

 

[Boats Rock]

Just remember they are stainless not stain proof. Mine had small spots also and when I took them to a propeller shop I asked the same questions. He showed me hundreds of props from aluminum and stainless to brass. He said all of the above to my questions. Stains and pits on stainless steel props can come from galvanic action,water conditions, air pollution,acid rain. and yes the quality of the manufacturing of the prop. So I had him recup the tips and clean the leading edges and I polished the crap out of them. Now you can see your face in them. I will see what happens this year. One thing he did say was to pull the props once a year and grease the shafts.

 

[twin yams]

i have a set of 15 1/4 x 19 polished yamaha props that i am not using, if anybody is interested in purchasing them send me a pm --they are in mint cond., with a tiny bit of the "rust spots"

 

[jekyl]

My 265 express with 200 hpdi's has 17 inch props ...there is no apparent pitch marked on them they are counterotating. She performs well but doesn't pull full revs (5800) any suggestions.....

 

[gradyfish22]

5500rpm should be max on that engine if I am correct. That is what Yamaha has listed. If you are turning over that, that may be a problem/issue and you would want to reprop the boat. Is that at full, half or light load? There should be a number inside the hub that says what the pitch is, it should say something like M19 or M17 if I am correct unless the boat has had a prop swap.

 

[BobP]

Are you having a Yamaha mechanic check out the engines?

If so, ask him to evaluate the props and tell you why this has occurred.

What are the condition of the anodes? Were the lower units kept down while moored?

Ask owner what paint, specifically, was used on nose cones.

 

[BobP]

HD Joe, the Yamaha dealer I bought my engines / SS props , included in the sale - could make one change in size if not happy with props, so it implies the props may have been used prior.
But not for long. They should look new too, no nicks, dents, whatever.
Just some grease on the splines.

They were not discounted in price. To me, it's actually a good idea, as long as they are mint or near mint. I guess one can demand sealed box, but better not come back to swap for another size.

That may be what occurred.

I think this policy may apply to other dealers too.

The dealer did offer me one prop used, used as in used if you know what I mean. He showed it to me first. It was discounted $100, I passed.

 

[Tuna Man]

Bob,
Yes a local five star Yamaha mechanic is going to go over the outboards when the boat is surveyed this Friday. I will get the printouts from his computer program. I will ask the type of paint (on the 'cone' of the lower unit and on the boat bottom) and the probable cause of the rusting. The more I think about, the more I think it may be from lack of use. The motors have less than forty hours on them and the boat is almost two years old since purchased. I would guess the boat has not left the slip in the last two months or so. I will learn more after this week.

The motors are left in the up position.
The anodes looked pretty good from what I remember, probably 90% intact (like I would suspect).

 

[BobP]

Good to hear it Tuna Man. I like it when a plan comes together.

The Yamaha mechanics don't come cheap, so you are entitled in my opinion to all the questions you have !

My memory is not what it used to be, I'd make a list not to forget anything !

 

[JUST-IN-TIME]

5 star is nothing to be proud of, anybody can pass
all it consists of are 10 Cd's which ?'s after wards
now if they guy has the other patches, now he is up and up

yami had a problem with cheap metal, see it all the time

exactly, stainless means it will stain-less

if the prop is making cavitation, the trim anode will be chewed up