This links to the contemporary L-Head (Flathead) service manual. You can download it from here (all 300+ pages).
L-Head Manual: https://docs.google.com/file/d/0B6NaqjIxWV1ycG8wd0s3Z2Q2X00/edit
Link to DIY GoKarts compendium of all Briggs Manuals: Online Service Manual Resource - DIY Go Kart Forum
L-Head Manual: https://docs.google.com/file/d/0B6NaqjIxWV1ycG8wd0s3Z2Q2X00/edit
Link to DIY GoKarts compendium of all Briggs Manuals: Online Service Manual Resource - DIY Go Kart Forum