I found this post on the Forum and it is how I did mine. Purchased the fitting from Tower Hobbies when I bought the engine.

With the back plate removed, motor upright, from the rear, you can drill the top left screw hole all the way through, just make sure you use a small enough drillbit not to damage the threads. Flush the motor out really well to remove metal shavings and replace back plate using a 140rx pressure nipple in the top left hand hole.
http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXWY11
You can also drill the hole out with the pressure nipple installed to prevent thread damage, as I recall, that's how I did it. Just use small enough drill bit to pass through the pressure fitting.


Ron9844