Outboard Engine Help

Plumbean · #1 (**permalink**) 09-12-2010

Wondering if anyone can help diagnose a problem for me. I have a 2 hp Honda 4 stroke engine that came with the dinghy for my boat.

The engine has been neglected for 2 years (my fault) and probably all of its life. When I tried to start it up this year, it smoked a ton (white smoke) and an oil/fuel mixture came pouring out of the exhaust and back through the air intake. Suspecting that the carb was plugged up, I removed this to find out that it is not easy to service. After trying to take it apart I managed to break a small piece of the float (grrrr) and then determined that the bottom half of the carb was very corroded. The drain screw was also completely stripped, making winterization look like it was going to be a chore. So I decided to invest in a new carb assembly (replacing the broken piece was not an option -- thanks Honda), which I just installed on the engine. I also changed out the spark plug, which looked like it was the original one.

So just started the engine, and of course the exact same thing happened. It starts up and runs okay for about 15 seconds when it suddenly bogs down and starts smoking. I can try and power through this, but eventually (after maybe another 15 to 30 seconds) it's really struggling. On shutdown, oil starts pouring out of the air intake and the exhaust. For what it's worth, when I pulled the spark plug and peered into the cylinder head at the piston, it is not nice and shiny but looks rusted. Thoughts anyone?

dabnis · #2 (**permalink**) 09-12-2010

Plum,

Had the same motor some years ago. Sounds like the crankcase may have been way overfilled or somehow fuel has leaked into the crankcase. Suggest
you drain the crankcase and refill, can't remember the amount, less than
a quart, I think. The Honda web site may have the specs. If it runs at all
the basics are probably OK. After you drain you may want to remove the plug
and with the fuel shut off turn it upside down so anything still in the upper
half of the engine can drain out. When not used for more than a couple of weeks the carb should be drained, taking the carb off is a pain, don't ask me
how I know.

Dabnis

Vasco · #3 (**permalink**) 09-12-2010

I may be wrong but I understand you can only lay these engines down one way. If you do it wrong, crankcase oil gets into the cylinders.

dabnis · #4 (**permalink**) 09-12-2010

Vasco,

You are right, I think it is posted on the engine. Never laid
mine on the "wrong" side so I can't say that is the problem
for sure. However, chances are pretty good that the "wrong"
side could be the problem or overfilling the cranckcase, or both.
Plum, main thing is to get the oil out of the upper end and start over.

Dabnis

Plumbean · #5 (**permalink**) 09-12-2010

Okay, so I'm showing my ignorance here, but how do I get the oil out of the crankcase? Is it as simple as pulling the drain plug under the dipstick?

FWIW, I'm aware of the issue re not laying it down the wrong way. Found this out the hard way when I first took delivery of the engine, but that was two years ago and it ran okay (not great) last year. I do not think it was laid down the wrong way since then, but perhaps I'm mistaken.

Thanks for the help!

dabnis · #6 (**permalink**) 09-12-2010

Quote:

Originally Posted by Plumbean

Okay, so I'm showing my ignorance here, but how do I get the oil out of the crankcase? Is it as simple as pulling the drain plug under the dipstick?

FWIW, I'm aware of the issue re not laying it down the wrong way. Found this out the hard way when I first took delivery of the engine, but that was two years ago and it ran okay (not great) last year. I do not think it was laid down the wrong way since then, but perhaps I'm mistaken.

Thanks for the help!

IIRC, I think you are right. I believe there is only one drain plug
on the upper motor housing, nothing else to drain. If it runs I doubt
that the pistion skirt is broken, no other way for the oil to get into
the upper part of the motor except by blowing back through the
crankcase breather, I think. Again, drain the crankcase, and then
remove the spark plug and turn it upside down to drain any remaining
oil iout of the combustion chamber. Don't overfill with new oil. Let us
know what you find, be interesting to know how much oil in total
you drain out.

dabnis · #7 (**permalink**) 09-13-2010

Plum,

Here is a list of owner's manuals:

Honda Marine - BF2 Owners' Manuals

It looks like the capacity is .26 US Quart.

Dabnis

Plumbean · #8 (**permalink**) 09-21-2010

Thanks for all the help. Looks like I have found the enemy, and it is me. Before trying to get the engine started, I added some oil without looking at the manual first. The only way to pour oil into this engine without using a funnel is to lay it down on its side. Being aware of the "only lay it down one way" issue, I was relieved to see that the oil filler is on the "up" side when the engine is laid down. What I didn't realize is that filling it this way it is very easy to overfill. The manual actually has you fill the oil when the engine is in the upright position.

So the other day I checked the level and realized it looked high. Not by very much, but definitely above the maximum fill line. So I drained some out (using an electric pump I have for doing oil changes on the mother ship) and tried again. She smoked a bit at first, but not anything like before, and then she settled down and ran for a bit. Haven't put her out on the water yet, but I think we are back up and running. Thanks again for the help and encouragement.

dabnis · #9 (**permalink**) 09-22-2010

Plum,

Good to hear you found the problem. The motor I had
was bullet proof. Short of running it without oil there is not
much you can do to hurt it. You might treat it to a new spark
plug with all that oil in the cylinder. Thanks for the feedback.

Dabnis