If the motor has a problem, such as valve clearance out of spec, or bad ring etc., you can spend days on carbs and get nowhere. A compression test is the simple way to tell if the motor is healthy (aside from obvious noises etc.). If the compression test turns out fine, and the motor starts and idles fine, but the motor runs worse as it warms up, then a valve clearance check should be done. Read the valve train warning in my signature before doing anything with the valve cover.
You should also download all of the manuals in my signature.
The compression test should be right around 180 PSI for each cylinder.
Next you verify ignition operation. You need to make sure all four are firing. If the water test on all cylinders is the same, then you can assume all four are firing. You then verify the timing per the manual using a timing light. You also verify the advance curve per the manual.
Without all of the above being correct, you will waste a lot of time chasing carb problems that may or may not exist.
