Sometimes it will fire right up but not run true and then it would begin to run fine. I've changed points plugs and wires and gone through the carb also.
Sometimes it won't start at all and spit through the carb or exhaust. When it does this it has no intake suction at all.
The motor is in a Gehl skid steer and doesn't smoke when it does run (doubt its bad rings then) No noises like lifters just normal noises.
I took the timing cover off and don't see any marking on the timing gears to check if its jumped time and having no luck googling it either.
The cam shaft has 2 bolts holding the gear on and the tension rub block is under the chain not above.
Ideas where to look for info or ideas of your own will be greatly appreciated thank you

 

Sounds like a sticking valve to me. Don't know anything about that particular engine though.

 

Valve cover off all the valves move normal not just the rocker arms. All I've been able to find on this engine is it was first made in 1959 and was used in the British made Ford Cortina (maybe) but the pix I found had a single bolt in the cam gear and the tensioner rub block was inside pushing out not outside pushing in.
Jumping timing is the only thing I can figure that would make it not start for hours of cranking then start and run like crap then come to life like a new motor.
Theres no smoke ever and no abnormal noises ever and total loss of intake vacuum occasionally.
I have another motor I bought that is supposed to have a knock in the lower end but I dont want to cannibalize it just yet but am considering pulling the timing cover off just for a look at the gears. I'm a mechanic and my mechanic friends are stumped! Any and all thoughts are GREATLY appreciated Thank you.