Yamaha F115, water in crankcase oil

[Mazanek]

I have a four stroke Yamaha 115 that gets water in the crankcase oil. Its a 2000, left hand rotation. Its sister engine on the boat has no issue. The water amount is very small, but after about 10 hours I can see the oil is a little tan and hazy. The other motor, the oil is still crystanlin and not cloudy. After 20 hours, its very obvious. <br />I brought it to a Yamaha dealer last December as soon as I first noticed it(still under warranty) and he found nothing. <br />Dip stick is sealed well, I don't think its dripping in from anywhere. Boat's kept on a trailer. Motor runs perfect, just like starboard one. No smoke, idles perfect, same power as other.<br />I'm bringing it back to my dealer, which is 75 miles from where the boat is. But he already had a shot at it and told me there's no way water can get in the oil. It's there.<br />Any advice would be appreeciated. Thanks in advance.

 

[enn]

Re: Yamaha F115, water in crankcase oil

Well there are several ways:<br />1)Leaking head gasket.<br />2)Crack in cyl heads<br />3)Other gaskets leaking.<br /><br />I have newer seen this before on an OB - on an Inboard you would pressure check the cooling system - dont know if that can be done on an OB.<br /><br />It could also be the engine runing cold (condensation) is the engine runing at the right temp? You coud get the oil analysed to tell if it is salt water (from the cooling system if you run the enigne in saltwater) or condensation.