Briggs and Stratton 675 EX series 190cc-will not start

[fogo]

Hello
First time poster.
I have a Poulan Pro mower with a Briggs and Stratton 675 EX series 190cc (model 126M02-0131-F4) engine.

Quite a reliable engine for the last 6 years. Yesterday while using it, the engine made a loud pop and died.
It will not start, but turns. There's compression and when I pull the cord you can feel air being pumped out without the plug hole.
When the plug is put in the thread just a single turn you hear a clanking noise when the cord is pulled. The piston is not hitting the plug.

I've included a few pics.

Can anyone help? I'm trying to decide if I should fix it or get rid of it.

Thanks in advance.

 

[ILENGINE]

When you turn the engine over do the valves open and close properly

 

[fogo]

When you turn the engine over do the valves open and close properly

Thank you for replying.

I'm not really sure what you mean by the valves closing properly.
When I pull the cord, I see the piston moving, in out, and do see the valve heads moving a bit up and then back down flush with the block.

 

[Scrubcadet10]

On one stroke the intake valve should open with the piston going down, when the piston comes back up to top dead center, both valves should be closed, piston goes back down valves closed, as the piston comes back up the exhaust valve should open.
Intake valve is the bigger of the two.
Does one valve open the same height as the other?
also, with the piston at the top of the cylinder, push down in the middle of it and see if you feel any play up and down without the crankshaft moving...

 

[fogo]

On one stroke the intake valve should open with the piston going down, when the piston comes back up to top dead center, both valves should be closed, piston goes back down valves closed, as the piston comes back up the exhaust valve should open.
Intake valve is the bigger of the two.
Does one valve open the same height as the other?
also, with the piston at the top of the cylinder, push down in the middle of it and see if you feel any play up and down without the crankshaft moving...

Thank you for taking your time to help.

I made a very crude video of piston and valves moving.

With the piston at the top of the cylinder I pushed down in the middle of it and felt no play.
My apologies for the camera moving back and forth. I was pulling with one hand and holding the phone with my other.

I'll make a better video later with some help.

 

[fogo]

Here are two videos of me pulling the cord, one with the plug in and one without.

 

[Rivets]

Either the blade is loose or you have an engine with internal problems.

 

[Scrubcadet10]

Agree with the above assessment ....
I have a hunch there is excees play in the connecting rod.....

 

[fogo]

Thank you for everyone's responses. Much appreciated.

I think it's time for a new mower.

 

[slomo]

That Poulan is not a long term quality mower, as you can tell first hand. Should mow grass with any other though. Saving money on a cheaper mower will only cost you more in the long run. Now you are looking at a new mower, see??

The new Toro Super Recyclers have a cool electric start feature. I was looking at getting one. With 5 Snappers, don't need one. Only looking for the wife as electric start is easier on a 4 foot tall boss of our family. Wife and I push mow on Saturday mornings for exercise. So romantic........

Then there is the undisputed king of all push mowers. Have to say it but Snappers still reign supreme. Talking about the Snappers from a real mower shop. Not the disposable toy models from Home Depot and Lowes.

slomo