I feel that this does still seem carby related to me, However if you are uncomfortable getting to that, we can go through the process of ruling out all possible alternatives, as that way we can be sure about the carby eliment, and you can feel more confident you are not risking the carby unecissarily.
We can start with checking the ignition timing, While this engine wil have a transistorised coil, and there for the actual timing is controlled by a computer module, you can still have some issues that can cause the timing to be out, these are mostly regaurding flywheel keys, etc.
To make the machine not kick at all, it would need to be noticabley out, get a long wwoden stick, like the handle of a small artists paint brush, and insert it into the spark plus hole untill it touches the piston, hold it fairly central, so that it does not fall to the edge of the cylinder, this will let you see where the piston is in it's cycle.
Now, do a spark test, and try to work out if the piston is pretty much at the top of the cylinder when it sparks.
