No manual exists that I know of, but it's not a difficult job - 30 mins approx.
1) Remove cowling (4 bolts).
2) Remove spark plug.
3) Remove head securing nuts.
4) Remove head. Knock free with a soft hammer.
5) Scrape all traces of old gasket from both head and block. Do this at TDC with both valves closed. Be carefull not to gouge the matng faces.
6) Coat the gasket with LM grease and position on block.
7) Replace head and tighten nuts securely. Can't remember the proper torque, but 25FT/LBS shoud be about right if you have a torque wrench.
8) Replace cowling.
Done!
phil_saunders@bigfoot.com
Phil Saunders
October 2008