I just start with the break-in, the manual say open the HN 1 3/4, but is too rich, I'm playing with the needles but I can not reach a fine tunning, I'm using A8 glow plug and 12x6 apc prop. When I take off the glow driver, the rpm get down even it shut off, at full throttle it sound like it was lean but it does not, I'm confuse...