2008 Honda BF8 Fatal Symptoms??

I'm the original owner. This outboard has performed flawlessly as a motor on a tender and sat for 5 years as well. Started first pull.

Which is why I'm heartbroken to say, it seems to be dying.

Symptoms

*Lower cylinder stopped firing, running on top cylinder only
*Pulled plug in lower cylinder to check for foul... had water droplets on it!
*Decided to run on one cylinder for a week or so (live aboard/traveling it's my only way to get ashore)
*It's now getting serious amounts of oil in the good cylinder from time to time, nearly stalling the motor, but then recovering after burning off the oil.

Questions:

1) Am I doomed?
2) Seems like cracked block to me to allow both seawater and oil in. Likely?
3) Any "it might be..." ideas?

Are you also seeing water in your crankcase oil? (Turns it milky.) Assuming you've checked Spark Plug firing.

There's an oil passageway from crankcase into head sealed by an 'O' ring installed with head gasket.

Have you done a compression check? And its pretty simple job to pull the head, be sure to notice timing marks on pulleys and flywheel (need to remove recoil starter to set accurately) to get cam belt correct when you reinstall.

I have a 1986 BF-100, the granddaddy of your's and mine developed a corrosion hole from water jacket into combustion chamber (after twenty years salt water use) and I had to replace the head, much less cost than replacing engine.

Really Great Engine you have. Does not look "Fatal" at all.

Best of luck with it and I hope it's just Head Gasket/'O' Ring for you.
Art
edit:- As I recall this oil passageway was just below bottom cylinder and if head gasket gave there, would cause water in lower cylinder and likely water in oil.

Thank you for the response. Was out of town for the week and will be getting into this project today.,,

pilotart said:

Are you also seeing water in your crankcase oil? (Turns it milky.) Assuming you've checked Spark Plug firing.

There's an oil passageway from crankcase into head sealed by an 'O' ring installed with head gasket.

Have you done a compression check? And its pretty simple job to pull the head, be sure to notice timing marks on pulleys and flywheel (need to remove recoil starter to set accurately) to get cam belt correct when you reinstall.

I have a 1986 BF-100, the granddaddy of your's and mine developed a corrosion hole from water jacket into combustion chamber (after twenty years salt water use) and I had to replace the head, much less cost than replacing engine.

Really Great Engine you have. Does not look "Fatal" at all.

Best of luck with it and I hope it's just Head Gasket/'O' Ring for you.
Art
edit:- As I recall this oil passageway was just below bottom cylinder and if head gasket gave there, would cause water in lower cylinder and likely water in oil.

Click to expand...

Are you SURE the "droplets" you saw on your lower cylinder's plug was water? I mean, if the cylinder isn't firing then it very well COULD be condensed gasoline vapors and not water at all. Have you verified that the lower cylinder is getting spark? You MUST do that before assuming anything else is responsible for the dead hole.

What kind of maintenance does the outboard get? As in; when was the last time you replaced the thermostat? Spark plugs? (NGK ONLY)
changed oil?. Any history of over heating?

Also, running and WORKING the engine on just the one cylinder could set up some "dynamics" that could cause damage to occur. I would get the oars out in the meantime if at all possible. These are very well made and robust outboards that will absorb a lot of punishment. I don't think I would give up on ANY Honda twin unless I saw molten metal and slag.
They can typically ALWAYS be repaired.

After a brutal 2 hours of rowing at my maximum physical capacity against current/wind (both ways) yesterday, fixing this engine is getting much more appealing.

Answers in bold below...

jgmo said:

Are you SURE the "droplets" you saw on your lower cylinder's plug was water?
Yes. Definitely. They don't evaporate, they bead up and don't smell much like gasoline.

I mean, if the cylinder isn't firing then it very well COULD be condensed gasoline vapors and not water at all. Have you verified that the lower cylinder is getting spark? You MUST do that before assuming anything else is responsible for the dead hole.

Both cylinders are firing normally, producing a good strong spark.

What kind of maintenance does the outboard get? As in; when was the last time you replaced the thermostat? Spark plugs? (NGK ONLY)
changed oil?. Any history of over heating?

Outboard history is as follows: Used daily for a few years, then sat for 5 years. Started first pull! Ran normally for a few months, then cylinder stopped working. Has ran flawlessly at all other times. Literally no problems, other than it not idling straight from the factory. I just idle it with the throttle. Throttle control jammed recently, took it apart and fixed. Oil and lower unit lube oil changed a few months ago as it came out of 5 year storage. No history of overheating thermostat working well. Water in the cylinder is literally the only problem other than it not idling since new.

Also, running and WORKING the engine on just the one cylinder could set up some "dynamics" that could cause damage to occur. I would get the oars out in the meantime if at all possible. These are very well made and robust outboards that will absorb a lot of punishment. I don't think I would give up on ANY Honda twin unless I saw molten metal and slag.
They can typically ALWAYS be repaired.

Click to expand...

Compression test resulted in 130psi in good cylinder, 90psi in water logged cylinder. Obviously a hole in gasket or head/block at this point.

Removing head to get at gasket/block now...

Going through the manual now and removing the cylinder head and/or block looks to be a mess of a procedure not well suited for those traveling on boats with limited tool rooms.

I'm trying to decide between having it fixed locally and just buying a more simple unit. Much of everything on my boat has been designed to run without a seawater interface, as invariably, this is the typical failure point in all systems (including this outboard now).

My boat has air cooled: refrigerator/freezer, air conditioning, generator (Honda based), etc. If fact, there are no thru hulls below the waterline in the entire boat. (outboard power in wells)

Maybe it's time to take the philosophy of the main boat to the dinghy.

Was looking at this as a more reliable replacement to the Honda:

http://mud-skipper.com/173cc-6hp-outboard-motor-system.html?gclid=CPOVoo3-6skCFcUXHwodLxINYw

No water involved, simple, cheap Honda engine can be fitted. If it breaks, $100 gets you a new one. Seems far more logical.

Outboards remind me of marine heads. An overly complex solution to a simple issue.

That looks like something I might want on board my 32' sloop as a "spare" anyway. I can't say I fancy having an air cooled outboard sitting down in an engine well....but then that's just me.

As I said before, I couldn't give up on the Honda. And, I hope you're prepared for a DRASTIC reduction in performance as compared to what the Honda gives. But....the Honda IS heavy...and pulling it out of that well from time to time for some needed maintenance might have me singing a different tune.

Just remember....NOTHING is trouble free....and the lower end of that MUD SKIPPER will STILL be hanging down in the saltwater to corrode and present you with a little surprise at some point....so it had BETTER be up to the task or it's back to the oars in short order.

Good luck.

jgmo said:

That looks like something I might want on board my 32' sloop as a "spare" anyway. I can't say I fancy having an air cooled outboard sitting down in an engine well....but then that's just me.

That's not what it's for. The main boat has a pair of new eTec 30's in the wells. It's a 50' performance catamaran, so no junk allowed aboard to slow it down. No spares allowed. Too heavy.

As I said before, I couldn't give up on the Honda. And, I hope you're prepared for a DRASTIC reduction in performance as compared to what the Honda gives. But....the Honda IS heavy...and pulling it out of that well from time to time for some needed maintenance might have me singing a different tune.

Yup. I'm ready. No more planing. Usually can't anyway with all the water cops and idle speed zones, so not too big a deal. and Exactly. Scratched up some paint on the main boat wrestling this Hoinda outboard up the steps. Realized it's not practical if it's older and will need lots of service now..

Just remember....NOTHING is trouble free....and the lower end of that MUD SKIPPER will STILL be hanging down in the saltwater to corrode and present you with a little surprise at some point....so it had BETTER be up to the task or it's back to the oars in short order.

Thanks. This outboard (like the ones on the main boat) won't be sitting in the water. My outboards retract clear of the water for sailing performance and I only dip the outboard on the dingy into the water when it's pushing the dinghy. It's clear and dry at all times when it's not actively moving the dingy... which is why i find it so absolutely crappy of the Honda to die from seawater issues. It's beern high and dry its entire life, only dipped in when I'm using it to go ashore in the dinghy from the main boat. Still has the original zinc, which looks nearly new.

The mudskipper thing is just a drive train that's sealed from seawater. Based on the thousands of hours I get out of the same Honda air cooled engines in generators, even running air conditioning 12-14 hours a day for an entire summer, I'm convinced this is more robust than a standard outboard drinking up seawater and corroding away.

Holds true for every other system on a boat, so should hold true here.... unless the drive train is cheap/garbage on the mudskipper. That's the only risk, as a commercial Honda air cooled 5hp engine is essentially indestructible.





Good luck.

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Thanks for the kind help and input. This Honda BF8A is for sale now in Miami if anyone wants to get the drop on buying it before I get it up on Craigslist. I figure return the favor... any reasonable offer accepted.