We also sell part no. 3420 aside from part no. 3412 of ARCO products.  Another outboard starter replacement for your 2 stroke Yamaha that should be 25 to 40 HP. Two stroke Mariner of 20 to 40 HP and Hitachi S108-80, S108-80A, S108-80B. It has 11-tooth drive gear.  The price is very affordable compare to others. You can use our very useful website to order part no. 3420 online: http://www.magemarinestore.com/ar34oust2.html. If you are looking for the correct part for your motor the application guide is made for you http://www.magemarine.com/arco/  or you can just email us the serial#, model#, how much HP and type of your motor at sales@magemarinestore.com.