Gear mesh on the 700 is very important as the main gear has a 0.7 mod (fine gear mesh normally found on 50 size heli’s). In order to mesh the gears correctly you need to adjust the main gear to pinon gear gap and also auto rotation gear to tail gear gap. This can be achieved by grinding down the nubs on the clutch block and plastic tail case (see photos). In addition you will need to replace the screws with standard non-specialty button head screws and use the specialty washers from the Trex 600. This will need to be done for clutch block, plastic tail case and engine blocks. This will give you enough play to adjust the mesh.
Upgraded Metal Clutch Block with Grounded Metal Nubs