Honda petrol lawnmower GCV135?

I have this lawnmower which won't start. I've drained the fuel, cleaned the carb, changed the spark plug. I've checked for spark and there's one. There's fuel getting to spark plug as it's wet when I've checked it. Any ideas?

OK, lets see: Fuel in the cylinder. Spark. Not running. Sounds like a timing issue. I'm not familiar with all types of engines and ignition but the basic function is that of a magnet passing a coil of wire. When it does it generates a field of magnetic energy. When that energy collapses it produces a high voltage spark. That spark has to happen at the right time. If it's not then there's a possibility the key pin between the flywheel and the crank shaft may have been damaged or broken. The process IS happening as it should BUT not at the righ time.

HOWEVER: I'd expect to see (or hear) a pop either out of the exhaust pipe or the carburetor. But it IS possible to fire the spark at the wrong time and NOT get anything in the way of a pop.

You say you cleaned the carburetor. OK. I'll assume you did it right. But I also have to wonder if you got the settings back where they were before you disassembled it. And in cleaning you need to clear All the passages completely. Anything that may have come lose could be stuck and clogging the carb. You cleaned it - but did you do so effectively? Just because the spark plug is wet doesn't mean anything other than gas is getting into the cylinder. If too much gas gets in there then the fuel/air ratio is off, and won't burn.

Which leads to the next question: Have you flooded it? Turn off the choke and set the engine speed to full and pull several times. It may take several pulls to clear the flood. But assuming you've done everything right - I'd check the timing.

Hope this helps.

It is almost impossible for the ignition timing to be off. The only way for this to happen is for the key between the flywheel and the crankshaft to shear. That only happens when you hit something and stop the engine suddenly. So back to the starting problem. If you have spark as you say and the engine has compression what is left is fuel. You say you are getting fuel but is it in the correct air/fuel ratio? My guess is the carburetor is the issue. It should be taken off the engine, taken apart and soaked in a quality parts clean solvent, rinsed and blown dry with compressed air. All passages should be probed and blown out again. It is usually best to put it together with a rebuild kit.

Thanks for the answer Tony I will check the timing out.