I want to lower my rpm/mph or in other words increase my mph/rpm. I purchased the 79 tooth rear sprocket for my F3. This is the sprocket that is used on the non-North American F3 models. I also purchased the shorter belt. The dealer installed the rear sprocket and belt. When I picked it up and started driving it home the check engine message came on the gauges and it would not shift properly. Took it back to the dealer. After a week and half in the shop, the dealer was informed by BRP that the error code is due to the sprocket change. On the F3's with the semi automatic transmission, the down shift points are programmed into the ECM or the TCM. The dealer put the original 89 tooth sprocket and belt back on and the unit works fine. My question is, if they run the 79 tooth sprocket on the non-North American models, can I change the ECM or the TCM to a non-North American and get the proper down shift points needed for the transmission? It would seem to me if I can change the ECM or the TCM (which ever unit controls the downshift points) to match the 79 Tooth rear sprocket ratio, it should work. Any technical information about this would be great! BTW, all F3s use the same front 29 tooth sprocket.