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Johnson 50HP 50ESL74M: power defect

I

ILVER75

New member
Hi

this engine does not function normally. I spent time for the diagnostic one:

flow fuelpump OK (good flow with the idling, very good flow in acceleration)
ignition OK(very good and powerful spark on the 2 candles)
compressingOK (always 12bars)
start ver easly

idling OKand stable

afterseveral minutes of idling in a large recipient filled with very clean water1m3:
1- the newcandle of top cylinder is brilliant and wet (as if the candle “is drowned” - inspite of a premium gasoline and power fiscal rating sparkles with the candle)

2- the newcandle of bottom cylinder is matt and starts has sorrow has to brown (sign ofthe ignition)

3- a waterdirtied by fuel (petrol + oil of the 2T): the fuel of cylinder 1 is not consumedand sets out again in exhaust and then is found in water


The engineachieves then its working temperature:

white fumeswith exhaust: I know that the base seal beween water pump and exhaust is OUT OFORDER > if I change it that should remove the white fumes


Conclusion:
no problemsof valves
too muchpetrol arrives in roll top > that drowns the candle > no ignition

Problems of carbu?
your opinion PLEASE thank you from FRANCE
 
Last edited:
Does spark jump a gap of 1 cm on both plug wires , yes or no ?----A hole in the fuel pump diaphragm would allow too much fuel into the top cylinder.----That leads to no ignition and clean looking candle ( flooded ) we call it here.----Does the hand pump go hard when you operate it ?
 
racerone said:
Does spark jump a gap of 1 cm on both plug wires , yes or no ?----A hole in the fuel pump diaphragm would allow too much fuel into the top cylinder.----That leads to no ignition and clean looking candle ( flooded ) we call it here.----Does the hand pump go hard when you operate it ?
Click to expand...

Hi Racerone,
Yes good spark with a gap of 1cm on both wires.
Yes the handpump go hard when I operate it with hand but no strong as steel > I can check if there is a lek between Diaphragm and the engine where is hole pressure from top cylinder > good idea :)

Thanks allot.
Welcome to other great idea ?
 
The clean sparkplug indicates possible problems such as ----Too much fuel from top carburetor due to sticky float / float valve.-----------Diaphragm ruptured on fuel pump.----------No spark at 12 atmospheres of pressure.----Bad sparkplug.------No crankcase compression.-------------Have you owned this motor for a while ?------Describe how this " fault " showed up.--------Any visible holes in the crankcase ?
 
racerone said:
The clean sparkplug indicates possible problems such as ----Too much fuel from top carburetor due to sticky float / float valve.-----------Diaphragm ruptured on fuel pump.----------No spark at 12 atmospheres of pressure.----Bad sparkplug.------No crankcase compression.-------------Have you owned this motor for a while ?------Describe how this " fault " showed up.--------Any visible holes in the crankcase ?
Click to expand...

Sticky float / floatvalve is closed and no fuel go trough in close position.
No holes visible in the crankcase
The engine sleep since 10 years and never restarted since. Before engine was good, but with sleeping time...

Thanks for your help
 
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