Loss of compression

I noticed while bush hogging today that I did not have the power I was used to. Engine revs up just fine but stalls under heavy load. After I stopped, I pulled the plugs and did a finger compression test. Three cylinders blew my finger out of the hole but one barely puffed. The engine starts and I hear no slapping or clanging noise. I am guessing a broken compression ring. I did notice a little more than usual white smoke but still not enough to be a mosquito killer machine. I plan on trailering the tractor home tomorrow. What other possibilities are there for this symptom. Should I check something else prior to pulling the head? This is a front mount distributor 8N.
 
White smoke is usually indicative of burning water/antifreeze.
You quite likely blew your head gasket.
Pretty easy fix on those flatties though.
 
Just a compression ring failing would NOT affect it popping your finger off of the plug hole.

(ASSUMING the side of the piston and the other two rings aren"t "toast", as well.
 
I would pull the side valve inspection plate/s and
see if one of the valves is stuck. I have also seen
cases where the valve seat has come loose and
holding the valve open. Most likely an exhaust valve
as if it were an intake it would cause it to be very
hard to start and really run bad.

Zane
 

I had the hood off and with the spark plug out and using a flashlight I can see one valve opening and closing. Is this the exhaust or intake valve?
 
I think Ultradog has you pointed in the right direction. You shouldn't be seeing any white smoke. That you do could indicated had a failing head gasket but didn't know it.

Colin, MN
 

OK I will look at that tomorrow. If the head gasket has an internal failure (I saw no external leaks) with a breach from the water jacket to the cylinder, shouldn't it suck water into the cylinder during the power stroke (both valves closed)? If there is a water passage into the cylinder, I should be able to crank s few cycles and swab inside the spark plug hole to test for moisture, correct? I know I will have to remove the head no matter what the problem is - I just want to go slow and check things before I do that.
 
Yes you could do that though it's a bit of extra monkeying around.
Another way to check would be to fill the radiator real close to the top and look inside for bubbles when it's running.
A real bad head gasket leak will blow a lot of water out of the radiator.
 
(quoted from post at 00:28:34 07/09/14) ditto what zane said. verify valves moving..

Removed head today after cleaning tractor. Valves move but head gasket was breached. I drained coolant prior to removing head and I found coolant in #3 cylinder even though #2 was the one with no compression. I cleaned head and deck. I placed head back on block and it had a slight wobble. I laid a straight edge on the head and could see some light thru the middle section of the head. I did the same to be block but did not detect any problem. I am leaning toward trying a new gasket without getting the head shaved. If I lay the head on the block, it wobbles if you press down diagonally on one direction but not diagonally in the other direction. It does not wobble if pressed down straight down the middle from front to back. I did see a slight nick on top of #2 valve. If I can get someone to take photos I will post. The tops of all valves have Ford logo, making me think there never has been any recent valve work done on this tractor.
 

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