here's some diagrams for ya
http://www.wheelhorseforum.com/files/download/808-tractor-1968-lawn-ranger-da-om-ipl-wiring-317a-318apdf/
http://www.wheelhorseforum.com/files/file/224-engine-tecumseh-h60-75117d-h60-75118d-om-iplpdf/
http://www.wheelhorseforum.com/files/file/2027-engine-tecumseh-quick-reference-service-information/
how about a minibike?
http://ohlssonandrice.forumer.com/topic/1168320/Micro-Power-mini-bike#.VGd3gPmG9sj
building plans:
http://www.vintageprojects.com/mini-bike/pocket-bike.pdf