How I fixed and engine with a 2lb sledge hammer.
One of my neighbors has a JD lawn tractor bought from Home Depot 4 or 5yrs ago.
Calls me and says he blew up the engine and wants to know where to get another one.
So I go over, take a look and battery dead, N/G, we boost the battery, get it running but only on 1 cylinder, I switch spark plugs and again only 1 cyl, same one hitting.
I check spark on the dead cyl, it's good, pull the plug and check compression with my finger over the spark plug hole and it has compression.
Next I pull off all the covers and find a mouse nest on the fins of the dead cyl. Cleaned all that out.
So why is this cyl not fire-ring? I pull off the valve cover and find 1 bent push rod for the exhaust valve.
I try to push the exhaust valve down, it doesn't move.
So I remove the cyl head and still can't move the exhaust valve, try some penetrating oil, no luck.
Next I remove the rocker arm and hit the end of the valve with a 2lb hammer, 1 careful firm tap. Now the valve moves free but only a little bit.
I then look at the guide and find that it seems to be not in place where it should be, too close the the small end. I remove the valve spring and retainers with my fingers, not easy to do but got them off.
I then take a small deep socket and pound the guide back in place with my 2lb hammer till it looks like the intake guide does.
Valve moves free and the same as the intake does.
I then take the push rod and pound it back straight with my 2lb hammer best I can to make it straight. No harden metal in these push rods.
Put the motor back together, try to start it and it fires right up, both cylinders hitting smooth and steady.
All this done with buying or replacing any parts.
Will see how long it lasts.