8n cuts out

Have a 48 8n. When used with my 6ft woods mower, it will mow for hours just fine. However, If I put a moderate load on it like cultivating or discing or plowing, it will start to cut out after about an hour of work but idles just fine. As a matter of fact, it will operate with out cutting out at about 2/3 throttle and only cuts out at full throttle or slightly less. Gas flow seems fine. I have put my hand on the coil when this happens and it is cool to the touch. I changed plugs and that did not make any difference. Plugs looked like they had been firing just fine. Any thoughts out there?

Thanks for your assista

I recommend this to everyone: until you are SURE your ignition system components are proper, it is exponentially more difficult to isolate other problems. It doesn't take much decrease in ignition performance to cause you chasing all sorts of ghosts. Verifying/fixing ignition deficiancies does not take much time and needs to be done more regularly than many realize.