Notices
The Boating Forum

05 Yamaha F250 water in oil

Old 05-17-2021, 01:14 PM
  #1  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jun 2009
Location: Steubenville, Ohio
Posts: 1,634
Received 319 Likes on 147 Posts
Default 05 Yamaha F250 water in oil

My motor over heated at wot the other day don’t know it it sucked up a bag or something. I started running in on one motor after a little while I started the overheated motor and it ran perfect at 4500 rpms on the way in except it was running 10 degrees hotter than the other motor. Once I got in I replaced the impeller the old one looked fine. Put it back in the water and it started to heat up again at wot. Cooled right down when I lowered rpms. Took it back to the dock and decided I needed some Tito’s. No more troubleshooting for the day. Next morning I get up and pull the thermostats that I just replaced before I put boat away for the winter. It appeared one was not seated right but can’t be sure. Anyways I put them in a pot on the stove and they opened perfectly. So I reinstalled them and took it for a ride. The boat ran great both motors ran at the same temp at all rpms. So I’m pretty happy thinking the thermostat not seated good was my problem. I docked the boat and my wife said there’s some white smoke coming out of the back. I shut it right down and pulley the cowling and checked the oil. The oil was very milky so I pulled the boat again and changed the oil. I figured I was better off to let it sit with clean oil instead of the water oil mixture. I’m thinking it might be a blown head gasket but I’d like to get some input from some other people here. I’m going to tear into it Saturday so we will find out. Couple more things the motor is run in freshwater and has 1400 hours on it. I bought it with 500 saltwater hours on it in 2012. One more thing, there is no sign of the exhaust corrosion issue on this motor. I had the power head off a couple years ago to install the speedy sleeve and new oil pump.

Last edited by mkalink; 05-17-2021 at 01:27 PM.
Old 05-17-2021, 05:30 PM
  #2  
Admirals Club Admiral's Club Member
 
Join Date: Jul 2020
Location: Middle River, MD.
Posts: 221
Received 85 Likes on 51 Posts
Default

I have a 2006 F225 in my garage, with water in the oil. Techs took it off a boat with twins and said it has the corrosion issue that probably ate through the oil pan.
If your plugs are clean, then it's probably not a head gasket. A simple leak-down test will confirm if it is or not.
Old 05-22-2021, 05:37 AM
  #3  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jun 2009
Location: Steubenville, Ohio
Posts: 1,634
Received 319 Likes on 147 Posts
Default

Started tearing into it today. The plugs all look the same. Leak down test to follow this morning. Completed the Leak Down testing of all 6 cylinders. Cylinders 1,2,5, and 6 all between 2 and 5 percent cylinders 3 and 4 were a little higher at 15%. I believe my problem is the power head gasket atop the oil pan. I replaced this gasket a few years ago when I installed a speedy sleeve and oil pump. Could also be corrosion but everything looked like new when I had it apart before. So as it sits now I am going to pull the power head and see what that reveals.


Last edited by mkalink; 05-23-2021 at 05:25 AM.
Old 05-30-2021, 03:38 PM
  #4  
Admirals Club Admiral's Club Member
 
Join Date: Jul 2020
Location: Middle River, MD.
Posts: 221
Received 85 Likes on 51 Posts
Default

Thanks for the update. Please let us know the answer.
Old 06-11-2021, 05:48 AM
  #5  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jun 2009
Location: Steubenville, Ohio
Posts: 1,634
Received 319 Likes on 147 Posts
Default

Well I pulled the power head gasket was fine. I just finished replacing the midsection thinking it could be a corrosion issue. The midsection was fine. So now I have piece of mind that won’t be an issue later on. Waiting for the head gaskets to arrive. I will update my findings once they are replaced.
Old 06-12-2021, 06:18 PM
  #6  
Admirals Club Admiral's Club Member
 
Join Date: Aug 2004
Posts: 691
Likes: 0
Received 135 Likes on 72 Posts
Default

Check the heads. They tend to corrode from the inside out. I had water in the oil and it ended being one of my heads was bad (small pit corrosion where the water runs through the heads).

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.