BF-50D run at3800 to 4500 rpm max

[Sylva-Ranger]

I every ones, English is not my langage but y will try to do my best to explain.

Honda BF-50d 50 hp 4 strokes Programmed Fuel Injection …………..Run OK for about 15 mins. than slow down and can't reach more than about 3800 to 4500 rmp

No light at ON the dash exept the green (ok) one. No check engine, overheat or low oil pressure light come ON when the troubles occur.

If you stop the engine and re-start, run good for some times and begin the same trouble……………….More the engine is warm and more the trouble come again quickly after you stop and re-start .

Sqeeze the primer bulb during engine running change anything.

the engine make that since about a month, new fuel in the tank change nothing, put a drop of Sea-Foam change anything.3 new spark-plugs change anyting.

Today i make a little tune-up : -Change the thermostat ans the impeller, both seems good.
-Adjust the valves, 2 of the exhaust just a little bit tight , adjust in the middle of the specs…
-Clean low pressure filter, Notting wrong , change the hi-pressure filter for maintenance but seems good to
-check code whith the jumper 070pz-zy30100 and have any codes in the memories.

I also check the 3 ignitions coil whit my ohmmeter, all 3 are in the specs (cold) , i take the fuel pumps pressure (cold)and in the specs (about 35psi).

Now i need to make a test on the lake, but i dont think the engine will be different because i don't find anyting wrong at the first view……..Probably bring a driver, my fuel pressure gage and my timing-light whit me the next time…..

Do you have idea ? Do you ever saw a similar problem on Honda engine like that ?

May thanks

 

[ahicks]

You've already done everything I can think of, so my next bet would be a fuel injection sensor misbehaving.

 

[Sylva-Ranger]

I also check compression 145-135-140 PSI, the voltage when engine running is about 14,5 volts.

One thing i can't explain………..I checked ignition whith my timing-lite during engine running idle (on muff) just to check and compare , and the lite don't light, or light verry erracticly on all the 3 cylinder……….And the engine running good at this time….

My timing lite is a good quality one (Ectronis-Specialties model 130) self powered model and the batterys are new......And work normaly on any other outboard, atv or snowmobile i've work to now…………..Is like the ignition signal is low, or the wires very insulated and cut the reading of the signal……….

For the fuel injection system and sensors, i supposed that if Something work bad during engine operation, the ECM is supposed to keep it in memory ? And/or the check engine light is supposed to turn on ?

 

[ahicks]

First, regarding running this engine on muffs, there is a water intake right above the prop that will be sucking air when run on muffs. It needs to be blocked, the engine needs to be run in a tub, or you need to be very careful, running it on an idle with plenty of water volume available.

Second, regarding a faulty sensor function throwing a signal, the idiot lights are set up for engine temperature and oil pressure only. The injected engines are not my specialty, so I'm not sure on exactly what sensors it's reading. Might be worth your trouble to check into that further.

 

[Sylva-Ranger]

Make a test tonight whit my dog ( can't find friend or nabor driver to help me) and the engine run ok and seems to run faster than before.

One time i think that the bug come again, but it was realy windy on the lake tonight and th e fuel lever was low on one fuel tank and the fuel pump probably take air whit the movement ok the waves, i switched to no 2 tank and i don't do again.

Just a curious thing, sometimes it's hard to keep a constant rpm near 4000-4500 ...…...the engine have the tendency to slow by itself below 4000 after a certain time , if run more than 4500 it,s ok ………..Maybe the friction of the remote control is to soft and change position whit big wave tonight at this particular speed………..if i slow down to fast from hi speed to idle , the engine have tendency to stall (stop) or near to stall ………

Maybe a bad TPS sensor or something but no codes and no check engine light comme on…….

Do you think the dealer can find more information about bad sensor whit the Honda code-reader tools than me whit the Honda Jumper ?



i will try a more run test another time when the winds slow down and no waves……...

 

[Sylva-Ranger]

First, regarding running this engine on muffs, there is a water intake right above the prop that will be sucking air when run on muffs. It needs to be blocked, the engine needs to be run in a tub, or you need to be very careful, running it on an idle with plenty of water volume available.

Second, regarding a faulty sensor function throwing a signal, the idiot lights are set up for engine temperature and oil pressure only. The injected engines are not my specialty, so I'm not sure on exactly what sensors it's reading. Might be worth your trouble to check into that further.

I ran it just a idle whit the muf, water comming by the tell-tale all the time whit good pressure but thank you for the information, your wright this engine have a intake near the prop.

this engine have 4 lights, one green when everything is ok, one red overheat, one red low oil pressure and one another red check engine………..In the Clymer manual it, seem that many différents thing can actuate Check Engine light.

 

[Sylva-Ranger]

Dealer say if "check Engine " light is not "on", thats mean theres no fault code store in the memory even whith the Honda's code reader.

Thats curious, i know many EFI engine can store some codes, even for an intermitant problems even if the light is not iluminate