Jim,
These are the Robart 635 RS (air up / air down) 90 degree units. (
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMUA8) I was going for the 730's (air up / spring down) but they are having problems with the locking mechanisms. So I hope to have these here soon and finish up the wings. Will be ready for the maiden soon I hope. We have a fun fly this coming weekend so I know I won't be able to have it done by then.
Take your spark plug out and check for spark. My unit was dead. I won't know what the deal is until I pull it down and take a closer look. May be the hall sensor......
Good Luck
MC