hi mate, i've got an old 6hp evinrude that i was having troubles with and eventually gave up on, it seemd to be continuously losing revs when in gear, but it would always start first pull and never stalled or anything, just wouldnt get up to max. revs. i bought a new motor, so its now sitting in my garage gathering dust, and i havent started it for about 8 months, but im sure it would start up again, or at least be good for parts.
send me a pm if your interested, we could probably sort something out.
cheers James