1. How do I find my serial number on my Troy-Bilt Horse tiller?
Your serial number is stamped into the top of your transmission housing. You will need to clean this area and check for the stamped numbers. Numbers on the engine, or raised numbers on the transmission, are not your tiller serial number and will not help you identify your machine. This link shows the exact location. https://www.dropbox.com/s/mpco82ojmyw7s8n/SERIAL%20NUMBER%20LOCATION.pdf?dl=0
2. How do I know if I need one belt or two belts for my Troy-Bilt Horse tiller?
Horse I tillers (serial numbers up to #314150) used two matched drive belts and a fiber reverse disc. These are referred to as "2-Speed" tillers. Horse II (serial number 314151 and higher) tillers used one drive belt and a rubber ringed reverse disc. The one belt is moved between the grooves (sheaves) on the drive pulleys to create a "4-speed" tiller. Moving the belt acts like a hi-lo splitter on a truck or tractor transmission, changing the gear ration and allowing you to select two speeds for each belt position by moving the hi-lo shifter on the right side of the transmission. If your tiller is original one easy way to determine if you have a "2-Speed" or a "4-Speed" tiller is to check your transmission pulley. A "2-speed" Horse has a transmission pulley with three v-grooves(sheaves). The matched set of belts run on two of the sheaves, while the fiber disc fits into the third sheave on the pulley. In contrast "4-Speed" Horse tillers have a transmission pulley which has only two sheaves and a wide flat area on the rear of the pulley. The single drive belt runs in only one set of sheaves, determining your gear ratio, and the rubber ringed reverse disc makes contact with the flat surface on the transmission pulley to engage reverse.
3. Which engine should I choose to repower my Troy-Bilt Horse tiller?
The original Tecumseh, Briggs & Stratton and Kohler engines are really good engines, but they are getting older and most of them have some sort of problems which are beginning to surface. The biggest issue for a potential new buyer is that some replacement parts for these older engines are no longer available. For instance, the recoil starter assembly for all of them, fuel tanks, etc., are out of production now. In addition, even when they were available these parts were very expensive. The best bang for your buck for repowering an old Troy-Bilt is the Harbor Freight Predator 6.5 HP engine. More than 6 HP is really overkill (the weak link is the drive belt system, not engine horsepower), and for the average gardener with the average needs, there is nothing better than the Predator engine. I’ve consulted with dozens of customers who have chosen this option and have yet to receive any negative comments. We get nothing from Harbor Freight for making the recommendation. In fact, I’m sure they don’t know we exist, but if you are interested in saving money and improving your machine, this is an easy bet. Here’s a link to the engine we have used in the past.
https://www.harborfreight.com/65-hp-212cc-ohv-horizontal-shaft-gas-engine-epa-69730.html