1995 ... Yamaha 50hp outboard engine ... model code F50 .. Four Stroke Engine ... Carb Model ... Any ideas anyone
Have on a couple of occasions been motoring alone around the 16 - 22 knots speed and the engine has been sweet, no misfiring, no abnormal emissions (Smoking etc)
Out the blue, the engine rev's are restricted as if the safety device has kicked in, though there is no audible buzzer warning. There doesn’t appear to be any overheating issue going on. With the engine cowling removed, the fuel filter is full and no sign of debris in the fuel filter housing.
With regards me being inclined to think its not overheating, I can actually place my hand on the cylinder head at various positions and the temperature is uniform and it appears to be no hotter on occasions when it’s been running trouble free (not scientific I know).
Water is pumping fine at various water outlets and when placing my hand in the flow of water it doesn’t appear to be any hotter then it has been over the many years we have owned it.
We cannot replicate this condition when running the engine with muffs … it simply runs fine, full rev range available.
The fuel-priming ball is as it is normally, and all cylinders appear to be effected, there is no misfiring on a particular single cylinder.
The engine can run fine for a couple of miles/kilometres at any speed we decide to run when the onset of the fault is sudden. We cannot anticipate when it is likely to happen.
Has anyone heard of one of these engine going into a “safe mode” when there is no apparent reason that it should. Are there any diagnostic to check out this system? … or is it likely to be some other cause you, might have heard about with these engines, and whats the fix?
It has us baffled .. any helpful advise would be much appreciated.
Have on a couple of occasions been motoring alone around the 16 - 22 knots speed and the engine has been sweet, no misfiring, no abnormal emissions (Smoking etc)
Out the blue, the engine rev's are restricted as if the safety device has kicked in, though there is no audible buzzer warning. There doesn’t appear to be any overheating issue going on. With the engine cowling removed, the fuel filter is full and no sign of debris in the fuel filter housing.
With regards me being inclined to think its not overheating, I can actually place my hand on the cylinder head at various positions and the temperature is uniform and it appears to be no hotter on occasions when it’s been running trouble free (not scientific I know).
Water is pumping fine at various water outlets and when placing my hand in the flow of water it doesn’t appear to be any hotter then it has been over the many years we have owned it.
We cannot replicate this condition when running the engine with muffs … it simply runs fine, full rev range available.
The fuel-priming ball is as it is normally, and all cylinders appear to be effected, there is no misfiring on a particular single cylinder.
The engine can run fine for a couple of miles/kilometres at any speed we decide to run when the onset of the fault is sudden. We cannot anticipate when it is likely to happen.
Has anyone heard of one of these engine going into a “safe mode” when there is no apparent reason that it should. Are there any diagnostic to check out this system? … or is it likely to be some other cause you, might have heard about with these engines, and whats the fix?
It has us baffled .. any helpful advise would be much appreciated.
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