2002 yamaha 4 stroke getting water in oil

[dogridgekraus]

I hope someone can steer me in the right direction on this.
IDK how I would diagnose this problem effectively.
Im getting water in the engine oil (2002 4 stroke Yamaha T8)
Does anyone have any ideas on this?
I thought about putting air pressure to the cylinders but am not sure on what to look for or effectively diagnose.I am reluctant on doing a teardown on the powerhead. It seems to run great aside from the obiouse.
The oil is a light brown color,looks like coffee...Im not sure on how much water is getting in the oil. It get discolored like that after one or 2 outings.
Just been changing the oil,& keeping an eye on things for now.Im afraid ill ruin the powerhead if I keep this up though.
I hope someone can help....
Thanks:Marty

[Nautical]

Some things come to mind: Short trips- Does the engine get hot enough to burn off the condensed water?, headgasket allowing seapage from the water passages into the oil.How is your thermostat?

[dogridgekraus]

The thermostat sounds like an easy thing to check.
So what could a defective thermostat cause to allow water to get into the oil?
Thanks

[almetelo]

It get discolored like that after one or 2 outings

With that much water in 1 or 2 outings I think this may be the probable causes but...

headgasket - if the motor have been ran hot (a few months ago when you fit the bearings on the crankshaft you installed a new head gasket?)

Gasket and seals under powerhead (have you installed new gasket /seals when fit the bearings on the crank?)

I guess the T8 gaskets are made of metal (not sure) so I don't think is about scrapping the old gaskets

Maybe head or block needed to be ressurfaced???

The problem developed just after the rebuild of the powerhead?

Not such probable with much water in 1 or 2 outings:

stuck thermostat or run the motor for a long time at idle or low revs - causing motor to run cold and not burn off condensation

overpropping- not reaching 5500- 6000 rpms at WOT

bad plugs - not getting motor up to proper operating temp


Maybe our experts can give you a better support.

[rodbolt17]

unless your getting water on a plug I doubt its a head gasket.
most likely a base gasket or an oil pan gasket.