merc 60hp -unusual sound on idle ?

aye capn · 03 June 2009, 14:46

I have had a 4 stroke merc 60 from new - now in 3rd year. I have a unusual sound on idle that comes & goes after running at speed etc. At first I thought it was just normal on these particular engines but recently I heard an identical engine which confirms this not to be true. It sounds a bit like a dry ball race running within the engine or something ?? I've mentioned it to the service engineer at the end of each year (now twice) but he can't seem to find it - which I suppose I could understand when restricted to running the engine in a barrel. I'm just a bit concerned before the engine leaves manufactures warranty. Anyone had a similar experience on this engine and if so - what was it ? The engineer did grease something at the base of the engine/ gearbox leg which I would swear helped a bit but its still there ?

9D280 · 03 June 2009, 15:43

Hi Aye capn (sorry, I fully expect a verbal slap for that!!), welcome to ribnet!

Does it sound any louder with the lid off? If you can get a day with flat water might be worth having a nose around with someone elase driving - you may be better able to pinpoit the source of the noise.

If you have reported it to the dealer whilst in warranty does that not mean if it disintegrates later you have half a leg to stand on?

Sorry I can't be of more help at the mo.

Turbodiesel · 03 June 2009, 20:20

Try this, When you hear the noise try pumping the fuel primer bulb, i have seen or heard in the past if there is not a great deal of fuel in the pump the pump can get noisey as it runs of the camshaft. If the noise goes away you might want to look at a new fuel pump. Just a thought and an easy thing to try.

aye capn · 04 June 2009, 08:36

Thanks for the suggestions so far. I can clarify that if left on idle 'in gear', the sound does not exist. Only on idle 'out of gear' does it seam to materialise. Sometimes its there sometimes not. Is it a noisey (dry) clutch /freewheel or something ??? Is it a neutral gear adjustment ??? I hope to launch again this weekend and try some of your proposals - watch this space! I don't think its a serious issue - its a faint noise - just a bit niggling thats all and I hav'nt heard it come from other engines. Otherwise I might add I'm more than delighted with a great engine.

m chappelow · 04 June 2009, 09:37

sounds like could be in gearbox ..any oil in it

m chappelow · 04 June 2009, 09:58

Quote:

Originally Posted by m chappelow

sounds like could be in gearbox ..any oil in it

is it a rumbling type sound

alystra · 04 June 2009, 10:50

I wonder if there's a steadying bearing half way up the drive shaft, like there is on my engine (Merc 90 fs). Opened a thread about it in Engines and Props, - Merc 90 fs. Problem with driveshaft, help please - (I don't know how to embed the reference, so do an advanced search for the thread), there's some pictures on it.

Lots of strange intermittent noises disappeared after I replaced it. Might be worth a look.

aye capn · 04 June 2009, 12:50

Thanks alystra, I think that could be interesting. It sounds like a faint dry whirrring sound to me - def not a rumbling and again its only apparent in neutral. I'm religious about servicing to maintain warranty so it would be unlikely the gearbox could be consistently dry of oil & if so I'm sure it would have failed by now.
This discussion is helpful. My dealer/service engineer would not make life difficult if there is a problem, he has a good reputation, but without the engine being in the water its hard to communicate and identify the actual problem with him. If I can persuade him to focus on and replace this bearing my concerns might be over...... ?

jyasaki · 04 June 2009, 15:48

Yamaha had a problem with a bearing on a shaft that would make a whine similar to what you describe. Apparently, they used a delrin bearing that was a little too tight. The shaft is towards the front of the motor, and is the first thing going into the leg behind the motor mount. A very liberal application of a liquid lube (WD-40, Boeshield, etc.) to the shaft so it drips down into the bearing takes care of it for a while.

That, of course, assumes it's the same problem (Don't know if yours was a rebadged Yam powerhead.)

jky

alystra · 05 June 2009, 13:54

Quote:

Originally Posted by jyasaki

............That, of course, assumes it's the same problem (Don't know if yours was a rebadged Yam powerhead.)

jky

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.

sam12345 · 07 June 2009, 19:38

We had this problem with one of our Mariner 75's.

The problem was a water pipe being pinched (down the back with the gear change rod, sorry cant think of the name but its lubricated and cooled the bearings).

Mention that to the engineer could well be your cause being as its a merc you have and a mariner we had the problem with!