That engine mount is an interesting design. The engineers/designers were up with the problem of designing a mount that would hold all engines in that class range, so they came up with a clamping system on both sides that clamp down and hold each engine mounting lug. Ingenious except for the fact that it’s pretty easy to mount it pointing to either side. Out of plywood the thickness of my engine mounting lugs, I made two plates that go around and capture the mounting lugs and are held in place by the bolts and the clamps for the clamping mounts. Easy way to make those is just put some cardstock underneath your engine mount lugs and trace around it. Those plates when in place keep my engine pointing straight ahead. The manual addresses the problem by describing a measuring process from the spinner backplate back to the firewall; measurement should be equal on both sides. Good luck in the trimming process. Most models I’ve flown have always needed something. You will have a great little flyer as you make the adjustments. Good flying to you.

Tom