right, this is what I reckon could be wrong.
If the blade was loose, it's more than a little possible that the last person to use it hit something rather nasty.
To check to see if this was the case, have a look at the blade. for safetys sake, take the spark plug out first, then tip the mower backwards so that the spark plug is pointing up towards the sky ( if you do it this way, you wont tip the oil where it shouldn't go.
Does the blade have a big nick in it, or a dent on the cutting edge? it should be straight, and uniform without a wavy edge.
If it does look like its bashed something, it's a fair bet that the aluminium flywheeel key has sheared in two. this will put out the timing, making it all but impossible to get going.
From what you describe, this sounds the most likely problem, either that or water in the petrol, which would also give the same symtoms of a cough now and again, but other than that, a steadfast refusal to fire into life.
if it's a briggs engine, there will be four screws that hold the engine casing on, you won't need to take the flywheel off unless you camn see that the key is snapped. you will be able to see the key-ways very clearly, if they aren't inline, then its been snapped, I hope thats the cause, it's simple to fit a new one, and will cost no more than a pound.
all the best
graham
if you need more detailed instructions, give me a pm with your phone number and a time when it would be ok to phone, and I will guide you through it.
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