30 hp mariner making a humming/winding sound

[Bosbok]

Hi i have two 30hp mariner and the one is making a winding /humming sound but it only makes it under load. i did find water in the gearbox oil, could it be that the gearbox bearings are damaged or what else can it be.

thanks

[Turbodiesel]

I would guess it would be the gearbox, but always very hard to say without hearing it.

[TheMadMariner]

Can't be sure, but a quick way to help you in the right direction is to check the bearings: get a good grip on the propellor and try to rock it side-to-side.
Also; set the engine in neutral and try to spin the prop by hand . It should spin freely and without making any weird/ grinding sounds.
My 2 cents...

[biffer]

ave you check the starter motor

[Bosbok]

Thanks i will have it check out