You can just release it as soon as you have stopped movement of the kick start lever. It doesn't matter. The purpose of the decomp lever is to push open the exhaust valve. This limits the building of compression within the cylinder and allows the piston to move up and go past top dead centre easily. We want the position of the piston to be on the downward stroke but only just! That's why i say to just move the lever down 50mm. This sets us up for (almost) two crank revolutions before the compression cycle occurs. The crank has the best chance of spinning fast to provide combustion (firing) and therefore easy starting. With the new EFI SR400 model, like the one i used, it is so important to get a good swing on the kick lever and not forgetting to follow through with a little forward motion like i say in the clip to again, get the crank speed up. The engine control unit (ecu) won't trigger for ignition unless a certain minimum crank speed is detected. This is to prevent kick back which can damage you and engine parts.
This is very similar to Old Indian Bullet /Royal Enfield 350 6 V (manufactured by Enfield India Limited). I happen to start one old model 1974 make even by right hand with a single push after actuating the decompression lever. So easy to start.
I was having to try 3-5 kicks "going by the book". I can't see around the gas tank so was having to "set" it by hand. This way I don't need the window. I went out and practiced your way and I think I've got it down pat.
