Engine help please

[cpurvis]

Remove the valve cover from the dead cylinder and see that both valves are operating properly.

 

[Dscag2021]

Idk, I know my limits, I don’t have a backup mower to try something I never done on this one, if I stood next to someone and handed them wrenches and was able to watch, I’d be more confident

 

[cpurvis]

Then take it to a shop.

 

[Dscag2021]

Yup, ugh

 

[txmowman]

Sounds like a failed ignition coil. A coil can produce a spark but not have the energy to fire the cylinder under compression.

 

[Dscag2021]

What would make engine smoke? Because it smokes now

 

[Dscag2021]

Most likely it has dropped a cylinder.

I did a compression test, one side has about 80-90lbs and the other side doesn’t. I’d say you’re correct. What would next step be?

 

[hlw49]

Not a good way to test for spark U need a 1/4 inch gap to simulate ign. firing under compression. In his first test the plug was bad see all the black crud on the plug that was unburned oil and it acts as insulation that is the reason the spark was jumping to the body of the plug which did indicate a good ign. system since it was probably jumping a 1/4 inch gap.

 

[Dscag2021]

Not a good way to test for spark U need a 1/4 inch gap to simulate ign. firing under compression. In his first test the plug was bad see all the black crud on the plug that was unburned oil and it acts as insulation that is the reason the spark was jumping to the body of the plug which did indicate a good ign. system since it was probably jumping a 1/4 inch gap.

One spark plug was cleaner than the other if that means anything

 

[hlw49]

U say one cylinder has 80-90 psi compression and and the other has none? Determine why you have no compression check and see if the piston is moving up and down. Take the plug out and stick something down into the cylinder and turn it over by hand. If it is moving up and down then it sounds like it would be valve related. If not then it probably threw a rod. The FH580V is an old engine and those things had a propensity to wear the top main bearing out. Unless you know a good machinist it is not fixable. Post the spec. no. and someone can tell you if there is a replacement engine for it.