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Honda 50 EFI problem

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cheetah catfan

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Hi all, just found your forum while searching for help with a problem I'm having with my engine.
I have a 2011 Honda 50hp EFI, I have had 6 of the previous carb models since 1999 so generaly know a bit about these engines which I have on a commercial fishing vessel.
Last few weeks I noticed the cooling water wasn't right and checked the oil cap and sure enough..thermostat had stuck open, had this happen numerous times over the years and just fit a new one and no further problems. As I didn't have a chance to change the thermostat immediately, I ran the engine like this for a few weeks. Yesterday while doing 3000rpm the warning buzzer started to sound and the engine managment light came on, I stopped the engine and restarted it and it ran fine. As soon as I reached the harbour I checked the oil and was shocked to see it almost double the mark! The oil was still the same colour but very thin, I'm pretty certain there was petrol in it and not water, although the oil cap was covered with white gunk. I then drained the oil and replaced the filter, filled with fresh oil and fitted a new thermostat and assumed that would be it, engine was then running fine, plenty water coming through too.
I then used the boat today and the buzzer and engine management light kept coming on at all speeds, each time I immdiately switched off the engine, left it a few minutes then restarted it, it then ran fine for a while then the same would happen again, happend around 12 times today. The oil is fine, water/thermostat is fine, I can't think what is causing it, anyone any ideas? Thanks in advance for any help :)
 
Help on most of the newer models is hard to get on the web...it has been my experience that because of the computer lashup that a dealer is the only real service out there on most problems...i am running a 2011 60 merc and found out that even the dealer people hook up remotely to the merc service centers almost immediately ....there is just a different maintenance plan out there today and very few of us oldtimers have the computer or the continuously updated discs to support it...having said that i have one question...was that gasoline in the oil instead of water?..or did you overfill on oil?i would check compression and then take it to a dealer for a computer hook up...
 
i am not a honda man but i just hated to see you hang with the question....we have several excellent honda people on here so one of them may jump in...
 
Several things could have happened. A couple are....

1. The thermostat was stuck open and the engine was running too cold and not burning all the fuel. The excess fuel then made its way past the rings into the oil.

If this is the case, you have changed the thermostat and changed the oil and all could be well with that part.

2. You have not properly broke in the engine during the first ten hours and the rings have not seated...thus the same effect as above. During the first 10 hours, it is not good to idle a lot. You need to run the crap out of the engine within the parameters of the breakin instructions in your owner's manual.

Ok...now for the alarm. If it is the "check engine alarm", that indicates that one of your sensors is most likely out of range.

It could be the O2 sensor, getting hit with fuel in the exhaust or the engine not running hot enough....it could be the map sensor. The map is in the intake and it is possible that the excessive oil traveled through the crankcase vent to the intake and messed up the map sensor.
It could be others...

You have to check for codes to see for sure. You can do it your self by shorting two pins together on the service connector. When you turn the key switch on, the check engine light will blink in various long and short durations. That will transfer to a code number, which then transfers to a sensor. At this moment, I am not sure what the wire colors are to short together, so I will check on a 40 HP (same basic engine as the 50) that we have in for service and let you know.

Don't mean to leave you hanging, but at least wanted to respond.

In the meantime, it would be good to check the spark plugs (they may be very fouled) and take compression if you have the tools to do so. If compression is not real consistant between cylinders, don't fear too quickly...your rings might just be carboned up from the situation.

Mike
 
On the red four pin plug on the port front side of the motor. Take a paperclip and insert the ends into the pin for the black wire and the other end to the pin for the light green wire.

Turn the key to on and count the flashes in order and let us know what you find.

Mike
 
Thanks very much for the replies, much appreciated :)
Had to run it today again the way it is, still the same alarm going off and engine managment light coming on....more worrying today after I came in I dipped the oil and I'm certain I could smell petrol in it again and oil level dip appear up a small amount :( Don't know if I am imagining it or not..but the exhaust seems to be smoking a little bit more than usual, not a huge amount but hadn't noticed it in the past.
Talking to another fisherman about it today and he suggested it could be the fuel pump gasket leaking? or water in the fuel filter ( although this would not explain the fuel in the oil)
Yes it was run in ok when I purchased it new, and serviced regulary.
I will try what you suggested tomo Mike and let you know how I get on, haven't check the plugs yet as they were quite new but I will check them first tomo.
Thanks again for your help :)
 
It could a leaking low pressure fuel pump. Tilt the motor up some to minimize oil mess. Keep the pump connected to the fuel lines and remove the two mounting screws. Once you pull the pump out, squeeze the fuel bulb and maintain pressure on it, check for leaks around the plunger.

Then manually push in the piston to see if there are any leaks around it.

If not, then it is most likely ok.

I do not know where you are located, but keep in mind, unless it is registered commercially, in the USA, it has a five year warranty...so don't go too far in taking things apart.

Mike
 
Thanks Mike, I forgot to mention I am in the UK and it is fitted on a commercial fishing boat as one of a pair of Honda 50hp's :)
I did what you advised today with the red plug, and turned on the ignition, it beeped once then the engine managment light flashed regulary with a 2 second interval inbetween? I was counting initially but left it a while and it stays the same, constant 2 second interval flash (I tried the same on the other engine just to compare and the light just stayed on with it)
I took out the plugs to check them, they were a bit dirty but I've seen worse, I cleaned them up and swapped them with the other engine anyway.
I had a look at the fuel pump but it seems to have 4 star headed screws which I couldn't remove, there is 2 bolts holing it to the engine but I can't get at the lowest bolt with the tools I have unfortunately.
I will need to run it tomo again the way it is..hopefully as long as the oil is ok I won't cause any further damage :confused:

Thanks again for your help, much appreciated!
 
Just to add..I went back for another look at fuel pump, I managed to get it off eventually..seems to be ok, no signs of any leaks when I pumped the fuel or pushed in the piston
 
The blinking is indicating an issue with the O2 sensor. It could be the sensor was compromised from the excessive oil/fuel level. The leads might also have been broken or the connector unplugged. Check the connections etc....hopefully, you find something simple. That is where your alarm is coming from.

I do not know if O2 sensors can be cleaned...someone else (Jimmy) may have some thoughts on that.



Mike
 
Thanks very much Mike, your help is very much appreciated. That's great to hear what sensor it is, I'm not entirely sure where it is located on the engine..I couldn't get a proper look today , hopefully manage to get a chance tomo when the tide is out.
I'll let you know how I get on anyway, thanks again!
 
The O2 sensor is located to the right and a little above the oil filter. Its connector is located just to the left of the oil filter. Hopefully, you messed up the connector or pulled a wire while changing the filter.

Mike
 
Well....today I managed to take out the 02 sensor, it looked a bit dirty so I gave it a careful clean. I decided to swap it with the one from my other engine just to make sure, the sensor on the other engine just looked the same to be honest so I gave it a clean also before I put them back in opposite engines. I started them both up and let them run a few minutes then switched them off, I then did the red plug test just to check...and the light is still flashing :confused: I tested the other engine and the light stays on ( as it did before )
I can't think of what else to try now? I'm puzzled!
 
Do not fear. You have to erase the code. There are a couple of methods depending on your safety landyard button. Do you have the kind that you can push the button and stop the engine with the landyard still attached? Or.....does the land yard require you to remove it to stop the engine?
 
Ahh! Thanks Mike! Yeah I have the the kind where you can push the button to stop the engine with the landyard still attached, 2011 models.
Thanks very much for all your help! :)
 
Put your shorting device in the plug.

Turn the key to on.

Then within 20 seconds of turning on the key, push the safety landyard button in 5 times, holding it down on the 5th time.

Each push should be at least .5 secs long and the time not pushing should be at least .1 sec long.

On the fifth push, you should hear two beeps and the check engine light should go solid.

Turn the key switch off.

If you turn the key switch back on, the light should still be solid unless there is a new code.

Now that you switched the sensors, take it out and run it and see if the trouble goes away or just transfers to the other motor.

Mike
 
Thanks very much once again Mike!
I did that today and managed to erase the code, was simple to do when you know how!
I ran them for a good while and no problems showing from either engine..so far,so fingers crossed! I won't get a proper chance to give them a good run due to bad weather here ,I won't get fishing for a few days but hopefully that is it! If the fault appears in the other engine I will know I need to replace the sensor.
Thank you very much for your invaluable help, it is very much appreciated! :)
 
The fault has now appeared in the other engine,same symptoms as previous, original one is fine,so I know for certain I will need to replace the 02 sensor now,pity..they are not cheap!
 
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