As a start, try here
<A target="_blank" HREF=http://www.dropbears.com/b/broughsbooks/nautical/evinrude_outboards.htm>http://www.dropbears.com/b/broughsbooks/nautical/evinrude_outboards.htm</A>
or contact Robin Curnow at robin.curnow@eclipse.co.uk - he may be able to direct you to a supply, or even have a manual there.