Mercury 125 Whining Noise

[manahawkin63]

I have a 2003 Mercury 125, When I run the motor for an hour or more and slow down to idle speed I hear a whining noise if I take it out of gear I hear the same noise (Like some thing was grinding or rubbing in the engine). If let the motor cool down and start it again the noise goes away. Any ideas what?s causing this.

 

[fragged]

Re: Mercury 125 Whining Noise

theres a good chance it is coming from your driveshaft bearing just below the engine.

drop the leg and grease the shaft splines and also a little way down the shaft
and re-assemble.

 

[Sunfish12]

Re: Mercury 125 Whining Noise

I'm not sure if you're hearing the noise at the top end of the engine or lower down. But a quick and cheaper check is to drop the lower unit oil and measure amount taken out and check for metal filings in it.

 

[fragged]

Re: Mercury 125 Whining Noise

a quick and cheaper check is to drop the lower unit oil and measure amount taken out and check for metal filings in it.

I've been searching the net for about a week now because my 115hp merc is having the same issues,
it is amazing how many mercs and Yams have this problem which is a design flaw, removing oil will cost
money but just dropping the leg and greasing won't as long as you have some grease.

Lift the cover off the engine while its running, the bearing noise appears to come from the oil
pump which is under the engine and below the crankshaft end.

A good test to see if it's the top bearing is a squirt of a teflon lube directly into the
shaft area, tilt the engine slightly up and have a look in the top of the cowling at the back of the engine
you can just see the driveshaft as it exits the oil pump.

Squirt a big load of teflon oil in there above the bearing casing and let it run down the shaft.

if that doesn't cure it then try the gearbox oil.