bf25a oil leak

Hi all and Happy New Year!
I'm trying to figure out what I'm in for with an oil leak. The motor's always in the vertical position an oil's slightly pooling/leaking from the back corner near the dipstick and coming out to the right of the exhaust. I noticed this after the last run after Christmas. When I checked the oil before we went I noticed it was above the full level and was dark but not leaking outside. I assumed this was because the weather was cool and it needs an oil change. The only different thing I've been doing is running it completely out of gas if I'm not running it for more than a couple weeks. I didn't smell gas on the dipstick today. The oil was almost clear and at the correct level until recently and even with it leaking it's still above full?! I'm probably not qualified to fix this myself so I just hoping for thoughts on what the issue could be.
Thanks

Check your breather hose...#13 http://www.boats.net/parts/search/Honda/Outboard Engine/1999/BF25AX SHA/MUFFLER COVER/parts.html

It is possible that when the oil got too high, the excess blew back up through the breather hose into the muffler...#3. The oil could have leaked down to the bottom of the muffler and leaked out the bottom, then flowed to the rear of the engine.

Pull the hose off at the valve cover and see if there is any oil residue in it. That may help verify that that is the source.

Lower the oil level or change the oil and then watch to see how the level changes. You said that you you did not smell gas, but it is very possible that you have oil fowled plugs at this point. Another thing to check to the cause of increased oil level would be a thermostat stuck open. The motor could be running too cold. Generally, you would notice poor idle and acceleration if the motor is not coming to temperature. If you pull the thermostat when the engine is cold and it is stuck open....that is your cause.

If none of that helps, then all I can suggest is to change the oil (fill only to about 1/4" below the full mark), watch the oil level and continue to check for leaks.

Mike

It hasn't idled right since mid summer but the oil level didn't increase and turn dark until recently. Does a thermostat go bad over time or is it a Now it works-Now is doesn't situation? How often should a thermostat need replacement? My motor's a 94 and I don't recall a replaced thermostat in the repair records I have and I've owned it for about 2 years. I'll check the breather hose, thermostat, and plugs this weekend. Hondadude, your help has put me on the water instead of at the boatyard before, thanks again.

Thermostats can go bad quickly or over time. Debris can build up or quickly stick in them, keeping them from closing or corrosion builds up over time.

If it has not idled right since mid summer, you just have to determine what caused what. If the thermostat is ok, then compare spark plugs. You might have one of the carburetors that has a stuck float and that cylinder is running rich. That plug will be very black compared to the others.

It could even just be a bad spark plug. Only use NGK DR7EA in that motor....no other brand.

Mike

Here's the thermostat. Not sure if it's stuck open or closed but I'm pretty sure it's toast. Just like you said hondadude, there's oil in the breather hose at the valve cover and the oil level is over full. The plugs are carbon fouled but dry. I'll be ordering a new thermostat and gasket, new plugs, and do an oil an filter change soon. I'll report back after a test run. Thanks again!