New to this forum; everything I've read so far is very helpful. Just had to replace the mixing elbow on the Yanmar and didn't have the service manual. Found it here:
http://www.wesley-craft.com/Excalibur/Manuals/Yanmar%203YM30%20Operating%20Manual%20YM_V2_21JAN09.pdf
http://www.wesley-craft.com/Excalibur/Manuals/Yanmar%203YM30%20Operating%20Manual%20YM_V2_21JAN09.pdf