hi im new to the site i just bought this motor and would like to know what year it is i tried using the sears web site to find this info myself but it only told me the hp. the model# 217-59462 ser# 204738 i would like to learn how to start it and make it run correctly. i have never sean a lean/rich knob on the front of an engine before. it also does not have the prop on it however it does have the plastic nut on the shaft the past owner nos nothing about this unit. husband passed on