Engine not running at all cylinders

[Anders aasberg]

Hi Have a old 60 hp 2 stroke autolube engine three cylinder.
It seems that it dont run al cylinders. there is no over heating and extra smoke.
Have change al sparkpuggs and new fuelfilter before i but the boat in the water. Engine was running properly until to day when it lost power and only 10 knots at full throtel. In habour i removed the sparkplugg cable on the top cylinder when motor was idleing ( I think you call it idle?) and there was no change in motor runnig.
Removed cable on the second cylinder then engine stopped. Did the same on third cylinder and the engine stopped. it seems that i have spark at the first cylinder. but its no change in the sound of the engine. what can be the problem?

Regard Anders

[rodbolt17]

lack of spark,lack of fuel or a blown piston.
test spark and compression if all ok repair the fuel system.

[Anders aasberg]

spark

There seems to be a spark... maybe its lack of fuel.. thanks for your response. Hopefully its not the piston.