well i gave it a try today. the results: while fueling it up it did not matter what position the prop/ cranshaft was in fuel was still getting into the carb. first time i opened the throttle there was close to a teaspoon full of fuel that came out.[&o] so i pulled the plug and it was soaked. so i disconnect the fuel line to the carb and with the glow plug removed and hit it with the starter to clear it out, while spinning the motor over fuel was coming out of the nipple like there was no tomarrow. so anyway i reinstalled the plug and left the line off, the motor ran until the extra fuel was burned off, than rehooked the fuel line the engine came to life like it should. it was loading up at a lower rpm 2800-3600 could not get it to hold a steady idle it's always changes several hundred rpm's. so i ran the engine up and it peaked close to 8900 rpm backed the needle off 2 -3 clicks and throttle back down to idle, which was around 2800-2900 than dropped down lower to2500 rpm but really sounded loaded up but it stayed running. so i flew close to one tank load.
so i tried the refuel thing again; well it put fuel right back into the carb again no matter what position the prop was in so if i want to start this engine i have to pinch off the line that goes to the carb to do it. one other thing is i tried to defuel it and the fuel line that goes to the carb was off and i could not get the fuel to draw out of the tank, i put the line back on and could get the fuel out and could see it was sucking the fuel out of the carb line and could hear air going back thru the carb throat and see air bubbles going back thru the fuel line. so some where the fuel flow is not getting shut off when it needs to be. the diaphragm looks like there are no holes in it. with the regulator body off i rolled the engine over by hand and could see the diaphragm working the way it should. do i need to just send it to ys and let them have at it? or should i try some other stuff? one last thing i also turned the regulator abjustment screw all the way down and when fueling the tank there was fuel still getting into the carb.