Hay i have a tecumseh formula 10 hp motor in my ride on ive tryed every thing cleaned carby out played with the mixtures it has fuel and it has spark but wont idle at high or low revs it trys to fire third or fourth pull but just coffs farts and carrys on it sounds like carby problem but i have tryed every thing i even bought a nother carby of a running motor but still wont start but still no change and it back fires a blue flame every no and again any help would be good because it is starting to get on my nerves.

 

Sounds like timing is off. Check the flywheel key to see if it is broken or carcked.