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Honda BF2.3D - Running Rough

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richma

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I have a ten year old tiny Honda 2.3 hp motor for my raft, that has run absolutely perfect until I messed up. In preparation for a multi-day trip I bought new 90 wt gear lube and some 10-30 synthetic oil for the trip. Being 70 years old, of course I started filling the crank case with the 90 wt gear lube. It came out of the bottle in a qt bottle "spigot" so I didn't immediately see my mistake. Being 70 years old I quickly figured this out and dumped that **** out. I replaced it with regular synthetic, about 3 times, then took it on the trip. I didn't see any reference to an air filter for this motor in my manual? How can a motor not have an air filter? About 40 miles in, my reliable Honda motor crapped out and wouldn't start. Almost like it got hot and went into an unhappy state. Hours later it started - what was I to make of this? So we decided to use the oars and save the motor for emergencies. Of course we had two severe wind storms - and the little motor that could brought us through this darkness. But it does seem to be running rough back at home. And it seems to be a little smoky? Gas is good, premium 91 - with no corn oil. My question is -- did the 90 weight gear lube that snuck into the crank case destroy my poor motor? I tried a new plug, no better. Almost seems like a funky carb to me -- but the smoke? Any ideas from a knowledgeable technical expert? Has anyone on the planet ever done this before?
 
Hi,

Well, I don't think your mistake "destroyed" your motor. Certainly hope not.

But that heavy gear oil....even diluted and flushed out with engine oil....isn't "healthy" for it.at all.

I suspect that most of the problems you are seeing probably stem from that gear oil entering the crankcase breather system and "mucking up the works" as grandma would say.

Item 3, the crankcase breather system filter, in the parts page link below, may have gotten saturated because of that heavy oil.


But, also, the breather tube may have gotten a "gulp" of that oil too. See the item labled E-15 in bold font...lower right of the page.

That tube leads directly to the carburetor air guide box to deliver crankcase gasses to the engine intake to be burned.
See item 1 in the link below:


If that tube is holding oil then you may see smoke for some time unless it's cleaned out.

The good news is that the symptoms are likely temporary. Cleaning those parts will probably clear things up quickly.

The bad news is, I don't know how difficult getting to everything mentioned might be.
It looks to me like some disassembly is required. I DON'T KNOW...I have never worked on one of these.

The other good news is that, if you do nothing but just change the oil again and run it hard things might just clear up anyway. I think they might but I can't guarantee that.

As far as air filters on outboards...
...not many have any. That's because the water is not a "dusty environment" that would neccesitate running one.

There are products available to help flush engines in cases like this....they include BG 44, Sea Foam and others. But great care should be taken using them in the engine oil as it's very easy to overdose and ruin your engine.

I hope this helps and that you get another 10 years from that Honda.

Good luck.
 
I use sea foam all the time in my gasoline, I’d recommend it there. The same sea foam I use in gas can be used in the crankcase, says so on the can, but I’ve never used it that way. My memory of reading about that is it’s only use for a minimal time, then do an oil change.

I’d suggest a higher dose in the gas, then see if anything more is needed. That gas treatment may rinse out all the fuel system passages, if any combustion gases there are causing any issues.
 
I’m over 70, I call what you did a brain faart. Perfectly normal, many people have them 30-40 years before us? :)
 
Thanks guys... I am so impressed with the expertise and human kindness you all displayed helping an old fart out. Rather amazing - and very much appreciated. I watched a youtube video on 2.3 carb cleaning... done that and now the darn thing is purring like a kitten again. I'm hoping I wont need to disassemble the crankcase down to replace filter #3. That looks way beyond my skill set. But I will find me some sea foam and run some in my gas and the crankcase, then change the oil for the 4th time. I'm guessing that may get me through another 10 years, if my old body parts hold out. Thanks again. Sincerely.
 
Well, it looks like you have everything under control. Not bad fer a young WHIPPERSNAPPER! ;>)
 
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