Small Engines (Lawn Mowers, etc.): MTD YardMan lawn mower, wire connections, idler pulleys

Question
I have a model 13A325402 8.5 HP yellow/green yard man (bug) mower that I bought from a neighbor 3 yrs ago. Not sure of age but think a 1999. Lots of problems with it but able to fix..up to now. I was mowing and suddenly it would not go forward or backwards and then cut off. I checked the belts and the top drive belt (V-belt) was worn out. After hours of working on it, I was able to get off the old and put on the new. This required removing the engine pulley with an impact wrench. After putting on the new belt, the forward pedal has no tension. The engine starts fine and runs until I remove my foot from the brake and it then cuts off. I have reviewed the manual and searched online but can't find the problem. I believe it has something to do with the idler pulley and the two springs (one spring is the line that moves the forward pedal) because of the lack of tension on the pedal. Can you please give me some help? I have noone to work on it and can't afford it, even if I could find someone. Thanks so much!

Answer
First look where the foot pedal attaches to the drive linkage. Follow the linkage along until you find the logical place a spring would attach to put tension on the pedal. Them look at the idler pulleys.  If it is flat it rides on the outside of the belt and if V on the inside. I would think that the belt to the transmission is always under tension when the pedal is depressed. Hook up the idler pulley spring(s) as needed.  Replace all belt guides and set them at 1/8" from the belt when engaged.  

If the engine cuts off when you let the brake go it is probably a safety switch in the run circuit.  Seat switch, brake switch, PTO switch, Key switch and wire connections.  Find the bad one and replace.  Use a continuity meter to test the switches.  

Then if the transmission will not drive look at the pulley on the transmission.  Be sure the key is good.  Be sure the linkage is properly attached and adjusted.  If it still will not work in forward or reverse it it more than likely the shift keys.  They are the sliding keys on the shaft the gears run on. Or it could be a broken gear. Thanks a look at these suggestions and if not found get back to me with more information.