Advice for non starting mower

The presence of oil on top of the piston may still be residue from when it was tipped over and hasn't been started to burn it off.
 
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No.
With the mower tilted back a touch & turning the blade around i see after a few turns oil in the bore.
One i dont see how the oil can go up hill but two isnt the oil scraper ring supposed to stop oil passing anyway ?
 
The oil isnt on top the piston but in the bore.
Ive cleaned it off but after a few spins its there again.

See attached photos of when i cleaned it then spun it a few times.
 

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That amount of oil isn't a problem, so long as the engine isn't over full. It will burn away when the engine starts.
Before you pop the head back on, give the engine a good few pulls just to ensure the valve seats aren't jumping....on occasion they can drop back into place.
John :)
 
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Dont have a clue BUT if i spin the blade one way there is no sound but if i spin the other way it happens.

Ive put my finger on the large valve & can hear the click but cant feel it.

Then i put my finger on the small valve & can hear and also feel the click.
 
Spinning the engine over & watching the large vale i see it open sat 6mm every time.

Looking at the small valve i see it open 6mm but then the next time it opens & clicks its only sat 3mm

Size isnt exact but when it doesnt open fully i hear the click.

So the small valve opens fully then next time much less then fully then much less then fully then much less

Same pattern every time
 
Interesting! Both valves should open the same amount so it looks like the exhaust valve has a problem.
Is there a tappet cover that is removable so you can check out the valve clearances?
Maybe there is a slipped collet in there.
A collet can be a simple pin in these engines.
John :)
 
If the collect was slipped then the issue should be the same on this valve & not every other turn.

Is there some kind of gear which rotates making the valves open ?
If so if it was damaged in a certain spot then that would be why its every other turn that its ding the half open part.
 
The valves are opened by the camshaft which lifts a follower, and the valves locate directly onto that. I've never seen a knackered camshaft but something is amiss.
The cam is driven at half crank speed and the timing can't slip.
John :)
 
Exhaust off & valve cover now also off.
I can see two rods coming out of the engine case which then push against each valve.
Using a screwdriver i held the small valve open & spun the engine around a few times.
There is no clicking noise.
Remove the scredriver & spin the engine & noise is back.
So the pressure of the valve spring is affecting the clicking to happen inside the case as with no pressure the clicking isnt there ??
 

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