As to getting the engine bolts off, if you remove the muffler, and take out the 3 screws not by the needle valve, you'll be able to twist the engine for access to the last screw, or take out one of the needle valve screws and twist that. ( just dissassembled my dads wrecked nextar) Then I took off the head and back plate, and used a q-tip and alcohol to swab the pieces of sandy grit out of the engine (gravel bank) and put her back together.... the engine that is, not the plane It was the OS 46fxi... I assume the same one you have?