Comments on: Outboard Lower Unit Crack https://www.tropicalboating.com/2012/09/outboard-lower-unit-crack Stories about Boats and Boating Thu, 10 Dec 2015 00:33:23 +0000 hourly 1 https://wordpress.org/?v=7.0 By: Dori https://www.tropicalboating.com/2012/09/outboard-lower-unit-crack/comment-page-1#comment-27567 Thu, 10 Dec 2015 00:33:23 +0000 http://www.tropicalboating.com/?p=7618#comment-27567 In reply to Tom.

I have a 1994 Yamaha 75hp 2 stroke with the same lower unit crack. I just purchased the boat and probably wouldn’t have if I knew more about motors when I bought it. The guy I bought it from told me that the crack had been there for years and it hadn’t changed. Anyway….just curious to hear if you are still running this motor and if there has been any change in the crack in the lower unit.

]]> By: Tom https://www.tropicalboating.com/2012/09/outboard-lower-unit-crack/comment-page-1#comment-1356 Thu, 01 Nov 2012 11:34:11 +0000 http://www.tropicalboating.com/?p=7618#comment-1356 I learned on Yamaha outboard discussion forums that this is a common type of crack. It is caused by salt water penetrating behind the bearing carrier, resulting in a reaction between the two kinds of metals and corrosion between bearing carrier and lower unit housing.

Repair options quickly approach the price of a rebuilt lower unit, since it has to be disassembled, welded, then machined to accept the bearing carrier back in place.

A local mechanic told me that sometimes these cracks will continue until a U shaped piece of metal falls off. He said that as long as the crack does not get past the oil seal and cause leakage, one option is to ignore it.

This is an old engine. Something else could fail while I’m waiting for this problem to finish killing the lower unit. I’d rather save pennies for a new engine, so ignored it shall be!

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