Murray 11hp riding lawnmower?

Ive replaced old batterywith a new one. Ive changed out the 15amp fuse. Ive put a new cellinoid on it. Ive put a new starter switch on. Still, i have absolutley no juice. It wont make a sound. Ive checked all the wiring. Its just "dead in the water" sort a speak. Ive checked the engage and disingage the blade switch. Idont know what else to do or check. Can anyone please help me? Icant afford a new tractor at this time. This tractor is 8 maybe 9 yrs. old. I have also checked the sparkplug.