Originally Posted by jyasaki
............That, of course, assumes it's the same problem (Don't know if yours was a rebadged Yam powerhead.)
Yes, It's a Yamaha powerhead. On mine it was/is a sintered bronze bush, presumably 'self lubricating'. It siezed. When it did the rubber bush it was housed in revolved in the shaft housing. As it was then a rubber bearing, it was well lubricated by water, not only because it's below the waterline when at rest, but also because there's a small bleed pipe running from the tell tale water feed to the shaft housing in way of the rubber bit of the bearing. I wonder why?
Could it be that Mercury realised the bearing was bound to sieze, given the disimilar metals, no grease nipples, relative inaccessibility and immersion in salt water, so arranged for it to turn into a water lubricated rubber bearing?
'Dry whirring sound ', exactly that. Changed the bearing over the winter. Couldn't hear it at the beginning of the season, but now I fancy I can just hear it again. Trouble is, as the season unfolds and my ears become
re-attuned to the engine I fancy I can hear all sorts of weird noises coming from it. I'm sure they're not there.