Here are some maintainance manal PDFs I happened upon:

EJ22 maintanance:
http://www.mygyroplane.com/overhaulej22.pdf 

EJ25 twin cam timing belt replacment:
http://eggenfellneraircraft.com/TimingBeltReplace.pdf 

EJ25 twin cam valve adjustment:
http://eggenfellneraircraft.com/TimingBeltReplace.pdf 

More articles here:
http://endwrench.com/main.php?smPID=HTML::home.html 

[ Edited on Feb 07, 2006 by GeorgeL ]