"Does anyone know a source for workshop manuals for small (eg Tohatsu 3.5) engines?"
Like these you mean? You didn't say if long shaft or short shaft or forward only or forward neutral but have fun with these
>>><A target="_blank" HREF=http://www.tohatsu.com/tech_info/manuals.htm> click here </A><<<
Thanks for that. I have an owners manual, what I am looking for now is a workshop manual, rather like the Haines Manuals, that explains the construction of the engine, and repair operations.