Legion
04.05.2021 2:52:48
Can we start with the year/hp/model number of your Johnson 6hp?
See full version: Johnson 6: No spark on both cylinders
Can we start with the year/hp/model number of your Johnson 6hp?
You mentioned fuel on the plugs. Did you assume there was no spark? or did you clean up the plugs and check for spark in the plug gap with them removed and touching metal,or checked for spark by some other means? The trip could have caused residual fuel in the crankcase to work it’s way through open ports or past the rings to the plugs, and a plug wet with fuel will not spark, as the spark current finds a conductive path from the electrode tip , down the tip’s insulator to the base metal. This is more likely to happen if it was stored or rode with the spark plugs pointing toward the ground , so gravity moved fuel to the lowest point in the cylinder, being the spark plugs. If you did not run the gas out of the carb before traveling, and the motor was on top of the car with spark plugs down, the carb could have emptied into the crankcase with road vibration making this more likely.
Dave
I test ran by Johnson six in a barrel about 6 weeks ago. Last week I strapped it on the roof of my car.
Drove 1200 miles to upstate NY and put it on a Feathercraft.
Will not start. Plugs show signs of fuel.
No spark.
What’s wrong anybody?
Dirty oil -- oil which has lost it lubricating qualities and thickness -- will add friction to the rod and crank bearings, piston rings and pins and scoring on the cylinder walls, raising the piston temperature. Piston skirts suffer the most severe friction of scoring and galling, which can melt the piston and rings. Also, improperly mixed 2-cycle outboard oil that does not have the proper amount of lubricating oil will cause rapid overheating. here
Pre-ignition results from hot spots on top of the piston when carbon builds up in the combustion chamber. The carbon burns from an afterglow when the carbon has no time to cool down, which causes a premature firing and heats the piston top. An audible "pinging" sound can be heard during idle or low-speed throttle operation. Heavily carbonized exhaust valves allow carbon buildup, as well as excess cylinder pressure. A misaligned head gasket which allows a part of the gasket to overhang into the cylinder can also cause a hot spot. [links]
A common cause of overheated pistons relates to insufficient fuel delivery to the cylinder to keep the temperature down. Idle mixture screws that have settings which are too lean will cause a lean air/fuel mixture, and too much air in the combustion chamber causes the temperature to rise. Kinked fuel lines and clogged fuel filters will also starve the cylinders. A rich, or wetter mixture counteracts the condition.
Detonation results when the combustion chamber contains two opposing hot spots which fire at the same time. It causes a mini-explosion, keeping the piston hot all the time with no chance to cool between strokes. Detonation is heard by a loud spark knock, and the resulting un-timed explosions can burn a hole in the top of the piston. [links]
One of the major engine failures of an outboard motor concerns the temperature and operation of the piston. Responsible for compressing the air-fuel mixture, then forcing it from the exhaust, the piston can overheat and suffer catastrophic damage from a number of reasons. If a boat owner knows what can cause a burnt or galled piston, he can initiate a preventive maintenance procedure to stop it from happening.
They also don't like telling anyone what the model of the motor is. Top Secret information. Not to be disclosed. here
Cylinders 1, 3 and 5 are on the right side when viewing the motor from behind. Cylinders 2, 4 and 6 are on the left side when viewing the motor from behind. [links]
No one ever seems to know how a motor is designed to operate. Mostly they seem to be looking for the part number that needs to be changed.
Cylinder 2 (left top) and cylinder 3 (right middle) do not normally fire when the motor is in neutral. If I am reading your words correctly these are the cylinders that are not firing on your motor. [links]
Then they want to know why it costs so much. Where it can be found at a price they want to pay.