Ferguson diagnosis

Ok, have a TO 20 with some engine issues I could use some advice. The tractor was purchased for my 9 y/o fist tractor. It runs, but lacks power. Some white smoke from exhaust. When running, it has what is best described as a hollow sounding miss, have not determined exactly where from it originates. It sounds like a backfire, but from within the engine is the best way I can describe the sound. Hoping to solve issue for him as he is anxious to use his tractor with mower and other implements, but as of now just doesn't have the power. I have replaced plugs/wires, verified they are on the proper cylinders. My choice next was either valve job or in frame overhaul unless anyone has other ideas. Money not as much an issue as time, so I would like to hit the most likely culprit first. Any advice?
 
First thing to do is a compression test. Look for differences between cylinder pressures. If there is more than 10 to 15 lbs difference, give each cylinder a few squirts of oil, run the test again. If there is substantial improvement, the compression rings are worn.

If there is a low cylinder, and the oil made little difference, likely there is a valve problem. Before pulling the head, remove the valve cover, check the valve clearance. Should be .014" hot. Also look everything over, check for broken valve springs, bent pushrods. Turn the engine through, look for stuck valves, or valve not opening as in a flat cam.

If the compression checks good, the valve lash is set, and the problem still exists, some other things to check are the points, distributor bushings, ignition timing, vacuum leaks, carb condition and fuel mixture.
 
I have no compression tester. Over the road truck driver through the week, leaving me only weekends to try and solve this issue. Already replaced points, cap, rotor, plugs and wires. Was going to by a rebuild kit, but unsure if a rings and sleeves or valve train the most likely culprit.
 
(quoted from post at 02:56:27 07/11/15) Ok, have a TO 20 with some engine issues I could use some advice. The tractor was purchased for my 9 y/o fist tractor. It runs, but lacks power. Some white smoke from exhaust. When running, it has what is best described as a hollow sounding miss, have not determined exactly where from it originates. It sounds like a backfire, but from within the engine is the best way I can describe the sound. Hoping to solve issue for him as he is anxious to use his tractor with mower and other implements, but as of now just doesn't have the power. I have replaced plugs/wires, verified they are on the proper cylinders. My choice next was either valve job or in frame overhaul unless anyone has other ideas. Money not as much an issue as time, so I would like to hit the most likely culprit first. Any advice?

Look at the old spark plugs...if they are black and caked with deposits chances are it's burning oil. If they are fairly clean looking then chances are it's antifreeze. Also when it's running smell the exhaust. If it's sweet smelling then it's antifreeze.
 
Another way around having a compression tester is to pull the coil wire and crank it through. Listen carefully to the engine as it turns through. You can hear each cylinder load the starter as it comes up on compression. If there is not a steady pattern, you will hear one cylinder turn through easier than the other.

Is the radiator loosing water, or the engine overheating, water out the exhaust? Those are signs of a leaking head gasket.
 
I once? borrowed? rented? a compression test kit from autozone. I liked it, so instead of bringing it back, I paid for that one.
A couple years later I guess I blew it up checking a diesel's compression. The cheap gauges don't go up as high as I took that valve job, a good thing, a bad thing.
But right now, you don't need to buy a good one... but the guys are right, you got something up with valves- I bet an intake valve the way you describe the sound... it 'could' run like that forever... but do check it out...
 
Latest update:
Pulled coil wire, no "dead" sounding cylinders. Smelled exhaust, smells, well, smells like any other gas exhaust. Ran through some manuevers with tractor. Seems to make the "miss" noise and show loss of power when pulling grade or throttled up as to put more torque to engine. Am thinking of buying a valve train kit and not the full rebuild kit. Think I am on the right track? Since removal of gas tank is neccessary to remove valve cover, I have not visually verified the valve components, but as I mentioned, I want to make the best educated guess as to the most likely culprit before I tear it apart. Am I on the right track?
 
I would suggest checking the timing, centrifical advance in the distributor and the action of the governor before going into the engine.
 
I'm not a big supporter of buying rebuild kits.

Couple reasons, you don't know what you will need until you get in there. Also good chance the kit will have a lot of parts you don't need.

Parts are readily available, I would wait until the problem is found, everything is disassembled, and inspected before buying parts.

Back to the problem:

Being the miss is more pronounced at higher load/RPM, that is leading away from a compression problem. Low compression is more noticed at idle, tends to be less noticeable at high RPM when everything is happening faster, overcoming he compression leak.

High end misses are typically associated with weak spark, (check spark at each PLUG) or breathing problems, like flat cam failing to fully open a valve (usually exhaust), sticking valve, broken spring, etc.

Also restricted air filter or exhaust can cause top end problems. Try temporarily disconnecting the air cleaner, removing the muffler.
 
Harbor freight has a fair one and reasonable priced cheap shipping and also coupon codes are available to save a couple of bucks. Bought one for my tractors a few years ago. Also bought their oil pressure tester
 
Time to take the fuel tank off and inspect the valve mechanism . To me it sounds like a broken valve spring , a common fault on engines that have sat for a while .
 

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