D8 13a Caterpillar Bulldozer pony compression trouble

I have been having trouble with getting the D8 13A running. Pont yrouble at this time. Was having spark trouble, fixed it,, then carb trouble and fxed that. Now I have no compression on the pony when i crank it I cranks with the starter, but like i say vary little compression. does any one have an idea as to what can be happening. Is it the vales? or the piston rings that might be dry?? What suggestions do you have? I did pour oil down the spark plug holes but no luck. Im starting to get frustrated with it.
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Remove the valve front plate inspection and check when you start if a valve is't stuck open or desajusted they should have .008 inch clearance between the end of valve stem and the head of the adjusting screw.
 
Could be valves, or rings, or pistons. Reminded me of a neighbor's D8. The compression was so bad that in order to start the pony engine, he'd take out the plugs and squirt #90 gear oil into the cylinders to hold compression long enough to get the pony engine started.

He did that for years; don't know that he ever overhauled that pony engine.
 
I have tried skirting oil down the plugs. But i didnt put that much of a thick oil, and it didnt do any difference. Before i stopedd it last time. It had good compression, so i am thinking there a valve stuck open.
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finally got the compressions issue resolved. I removed the front plate cover like recommened and there it was .. the two middle vales were stuck open. a little bit od penetrant and a slight tap and got one loose, the other one took a littl emore effort. but got it loose. now again my carb is giving troouble. previouse cleaned last week, it did not want to completely fill the float area. and somehow the fillter got dirty again. must of been stuff inside the tank.. but i dont understand why it didnt attempt to fire up when i pourd little gas down carb or ether? could it be bad spark plugs?? I already have spark and compression?? any ideas?

thanks
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