I recently installed a new OS .37 ring engine in a Caliber 30 and it appears to lack sufficient output power. The chopter hovers at a 3/4 throttle setting and is pulling only 5.5 degrees of pitch.
Inorder for the engine to get the helio to hover I have to screw in the HS needle valve a half turn out from the fully closed position. I'm using 10% fuel.
Any suggestions in what may be causing my problem?

What temp is it running at?

Sounds like it is set up screwy. Is this your first heli?

Are the ATV's or end points equal on both sides of the throttle? If not then 3/4 stick isn't 3/4 throttle. If you used atv's or endpoints that are more than a couple percent different then you've introduced differentail throw into your throttle and that should really be fixed before you go any further.