We have 3 Walkers 2 of which are 26EFI and one 25hp model. Our 25hp model bent a valve so we opted to put in a new 25hp Kohler motor, Anyways Walker now has a updated pully KIT which is the crank pully and upper pully's, we had them put the lower pully on and kept the Walker speed up kit on it and the results were the same speed! (YES THE SAME SPEED )as our Toro Z-Masters!!!!!!!!! If you want to up the speed on your Walker look into it. For you guys with mulching decks and discharge decks you will stay with speeds of Toro and Exmark and we know cause we run them all!