Runs only wide open throttle bad

[Ollison]

I have been  A mechanic for years. I change the spark plug adjust to the valves replaced the carburetor supposedly pre-adjusted and it still acts the same. Starts when cold pretty good. When you run it it doesn’t quite open up. After that it’s down hill. Runs worse after warm up.  It will not idle you want the idle screw turn all away again. I also changed your fuel filter. It’s seems to have compression. Cranking my it by hand is difficult testing compression. One unusual happening, that hasn’t happened for awhile is it seemed to be locking up when I tried to crank it. It’s in excellent shape body wise. What am I missing here. Yes it does pump gas fine. 

[CROSSBOLT]

Too many questions: 1. Why replace carb? 2. Was carb replacement exactly like original? 3. Was original the correct part? 4. What clearances were valves set? 5. Why change spark plug? 6. What did original plug look like?

[eamartin]

Staying with the carb theme:   How a about a carb photo?  Does the carb have the electric bystarter?  How many turns out from seated is the slow jet screw?  Does the  carb have the stock filter set-up?