Originally Posted by
Sir HC
For hot starts, I like to prime for about 5 seconds, but with the mixture at idle cutoff. This cycles cooler fuel through the system (unfortunately not the injector lines where it's needed most though). Then crack the throttle a 1/4" before hitting the starter (the goal being in the vicinity of 800RPM once running before bringing the throttle all the way back to idle). Count to three once she fires for the first time before slowly pushing the mixture forward or else you will get a slow/black smoky start. Then pull the mixture back to LOP until you're ready to do your runup.
As you get comfortable with it, experiment with it a bit so you have an idea whether it's rich or lean on any given day/temperature, and if in doubt, properly flood it and then start it with the throttle wide open and mixture at cutoff, making sure to pull the throttle back AS SOON AS it fires then slowly pushing the mixture forward.
Pretty much same procedure with HIO360 which is the basically the same engine minus 2 cylinders in a 269C helicopter. You get good at it and you don't have the luxury of any flywheel action from a prop! Have used the same procedure with a 540 like you and it works.