The mower start fine, hits operating Rpm and idles. When it gets warm I will get a pop, I think its pre-ignition but am not certain. When I load the motor the pop goes away. Starting while warm the motor will pop and hesitate, I have learned to just start cutting and the issue goes away. I am thinking the advance is may be too much in the cdi, as there were many different models for the same cdi. Looking for some advice, might need to find another replacement.
Don't know what an M model is, but if it is a 3000 rpm tractor motor I have not heard or seen evidence that any advance is applied. It is in coils for 2 stroke motors. The cdi I had many years ago depended upon a breaker point system to trigger it and so it depended upon the mechanical bob weights in the distributor for advance. Hope this is of some value?
Pulled carb and cleaned all the jets ext, still had issue. Pulled out idle jet, took out my mini drill bit set and used the #77 one size bigger than hole. Put it back in and started, immediately the issue was gone, go figure. I cleaned idle jet and re-installed and still had running issue, did not correct until I drilled hole bigger. Short video; can hear the before and after.
