[DaveO430]

Have you rechecked the compression after reassembly?

 

[DaveO430]

The compression is the same than before.

9.8 bar should be enough compression. You probably have a problem with the carburetor or ignition.

 

[DaveO430]

try compression check with the carb slides and and butterflies open. you may just find BOTH problems. a vacuum test will give clues too, but since you have limited data, just pull the slides and hold the throttle fully open and run a compressio tes again. make sure battery is fully charged between each cylinder test.

No need to pull the slides.

 

[DaveO430]

there is if a slide is not rising, or is stuck.

Even if, there is still plenty of air passage under the slide for a compression test.

 

[DaveO430]

Too little shim gets valve train noise, too much stops the valve from closing completely.