Corrosion in Yamaha Prop Shaft housing

Angler1

Cadet
Joined
Mar 17, 2012
Messages
27
Hello,

I have a 2003 Yamaha F225 on a deck boat I purchased used and had it few seasons already. Doing winter maintenance, I took the prop off and found white "acne" like corrosion spots on the inside on the shaft housing. These are on every component, inside of housing wall and on the shaft housing. It's not "bad", but it's there, maybe 2-3 spots per square inch. There is no loose corrosion debris accumulated anywhere, just the corrosion spots.

I know that my year engine has an exhause corrosion problem, and pictures I found look exactly like the same corrosion, except that the pictures are always from the powerhead, or down into the exhaust casing. Can't find any of the prop shaft housing (except one - showing a pile of debris that came from the top..but no corrosion actually in the shaft housing).

I did NOT notice this last year and I think I would have. I normally tow my boat from lake to lake, but this last year the wife talked me into keeping it in a slip at the local river marina all season. I always fully tilt the lower unit out of the water when not in use. However, I expect water would sit in the prop shaft housing. The engine has never been in salt.

My question is - is this corrosion a common item for moored boats. Or is this possibly a sign that I have a F225 with the notorious corrosion problem occuring.

Depending on the answer, I may not keep it in the river anymore....but is there any recommendation for retarding this..like soaking it in WD40 or something.

Thanks
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Corrosion in Yamaha Prop Shaft housing

It sounds like you don't have much of a corrosion problem, but you could pull your boat out, remove prop, clean all corrosion spots, prime and paint, Or, clean all corrosion spots and spray the entire area with white lithium grease, let it set up good, replace prop and forget it.....all depends on how worried you are about it....
 

Angler1

Cadet
Joined
Mar 17, 2012
Messages
27
Re: Corrosion in Yamaha Prop Shaft housing

Thanks for your feedback.
I'm not real worried if this is common to find some corrosion in the prop housing, for a boat stored one season in the water. But since some 2002-2003 Yamaha F Series motors have a known factory exahaust corrosion problem, not sure if I could have a bigger problem coming. I understand the corrosion problem ultimately leads to power loss and engine failure as it eats through the exhaust manifold and bottom of the power head.

It would be difficult to prep it enough for painting in there, but a little intricate brushing and white lithium is doable. Short of someone telling me to take it apart now....I'll do that, put the prop back on, store it for the winter and see what it looks like end of next year!

Thanks
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Corrosion in Yamaha Prop Shaft housing

My best guess would be that most "excessive corrosion" problems are with saltwater motors.....
 
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