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BF8A Oil Coming from Breather at Carb

camper8251

New member
Hello All:

Need some advice please. I have a BF8A serial BZBC 2100802. The motor has not been run in about two years. Started it up and seemed to run good. The Pee Tube was not spitting water so I shut it down and cleaned out the tube. Started it back up and let it run for a while and all was good. Shut it down and went to start again and oil started leaking from the Breather tube at the carburetor. Any ideas whats going on here?
The motor has been stored the last few years in Vertical Position on boat.

Thanks for your time!
 
Hi camper. Welcome to the forum.
Is that a P3?

Anyway as to your question:

There can be many reasons for oil coming from the breather but the first place I would check is the breather valve itself....item 3 in the link below.

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/8hp/bf8ax-xa-1999/cam-pulley

Many times, when an outboard sits for a long time, critters, mostly spiders, will decide that cover is a great place to live and raise a family. The resultant webs or nests can end up interfering with the valve. Taking the cover off and cleaning things up can restore proper breather function. Also, make sure the tubes are clear of debris or spider webs and replace them if they are deteriorated. At a minimum the cover oring will likely need replacement.

Hope this helps
 
Thank jgmo. I saw that device and figure it was something like that. Just ordered the manual for the thing so not sure what is what with it.
So is there supposed to be a lot of pressure coming out of the dipstick / Fill / Check port when its running?
When you say Cover o-ring. what might you be referring to? #23? I presume?

I had it running and Opened it up and there was a lot of pressure at that point...

And yes that is a P3... The mighty Orion.. Good Eye, not many know what that baby is..LOL Nor will many after the next couple years as it is going adios.... :(
 
My father in law was one of the Naval electronics techs that flew in the P2 as they developed the iconic "tail stinger" radar array system was the beginning of modern sub detection and AWACS. I don't know all the details but I'm an aviation admirer from childhood and get excited about pretty much any airplane that's in view.

Some history on your outboard might tell me more about what's happening. Have you owned it long? Was it fine before it sat for so long? Has it ever been overheated?

It's not a great sign that it's blowing out of the dipstick tube and oil fill. But there are a couple of things that you might still be able to try before a tear down depending on how you describe previous operation. Checking and cleaning the breather housing is the quickest, easiest thing I can think of.

Yes, item 23 is the oring I was referring to.
 
Ahh the P2 Before my time. Final duty station was Whidbey Island WA. They had P2's there before my time.

I am the original owner of the motor... Always runs great starts right up, very low hours on it as It hasnt been used a lot in the last 6 years. It is starting and running fine as of now, I think it had bad gas in it so I put the external tank on with Clean gas... Oil seemed to blow out the intake when it would stop running or it was having problems running on the old gas. Do you think I still need to dive into it since it is running fine now? I didnt recheck the pressure at the Dipstick tube last time I ran it though.


Thanks for the info....When I go to replace the plugs and change the impeller I will check the breather... But I imagine that wont really help if I am getting pressure at the Dipstick tube seeing it is way before the breather........

I am currently out of town on business and will work on it when I get back, I purchased new plugs and impeller for it....
 
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Were you P3 crew? Maintenance? Just curious.

Anyway, if good fuel solved the problem, I'm not one to argue with success. I've never seen bad fuel causing this sort of issue but we can make a whole new world from things I don't know or ever experienced.

And, I can see how, what was likely partial combustion, causing some strange things to happen in the cylinder while the intake valve was open.....maybe. There would be "stuff" like unburned bad gas and a little oil that might not all get past the exhaust valve. And due to a thing called "overlap", where the intake valve opens just slightly before the exhaust valve closes completely, anything that was still struggling to get out of the cylinder through the exhaust , might be forced out the intake. That's my theory and I'm stickin' to it until a REAL engine expert says I'm full of it. ;>)

Anyway, it seems she's back to form and that was a good call on fresh fuel.

I agree that going in and cleaning the breather and swapping in new plugs is a good course of action. I would also look carefully at the timing belt for stretch or cracking and verify the timing marks line up correctly.

Also, checking/adjusting the valve clearance every two or three seasons is something that should be part of keeping her tip top.

Don't forget to run her dry AND drain that carb for any lay up lasting more than three or four weeks....less if no Stabil in the tank!

Please update when you get back to it and let us know about any additional observations.
 
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Yep Crew. Enlisted Flight Engineer when not flying Structural Mechanic.. Good Times......Better Flying times though.. ha ha

Cleaned plugs and check breather etc. All looks good. Not sure about the back pressure thing but she seems to be running ok with no more oil coming out.
Will take it out in a week or two if weather cooperates and see how it goes!

Thanks for the assist.
 
I hope you got it and no more trouble. I was happy to TRY to help but it seems you figured this one out yourself...giving me a lesson along the way!
Please let us know how your test run goes.
 
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