RE: trubble starting my zdz 50ng
You are CERTAINLY over proped as Mike says.. go to a 22X8 ;I run a ZDZ50NG and have yet to go to a 22X10 the recommend prop AFTER break in as Mike says and he KNOWS .A 22X12 is way too much prop ! I have been running mine in a Great Planes Extra for several seasons now with great sucess by following Mike Dooleys qualified instructions to the letter.
Once you decide to go with the correct break in prop(22X8) I strongly suggest you go with a 32-1 mix of NON synthetic 2 cycle oil ,that being said and if your engine is not toast as we say.. start by opening the throttle fully,(ensuring that it is so) ,add full choke and flip the engine smartly 10 times or so,then ensure the choke is off and throttle retarded to idle ,turn ignition off and on again and smartly flip the prop-- if after several flips it is not running "cycle" the ignition switch again, open throttle to full open apply full choke (ensure it is so)and flip it over smartly and it should fire..Now turn off the choke retard the throttle to idle again and smartly flip thre prop. I have found it helps immensely to flip the prop over as strongly as you can,which greatly aids the starting process .
In closing I hope you will accept Mikes advisement he KNOWS ZDZ engines period![8D]