I cannot get this engine to make a transition from idle to full throttle b/c when idling it is loading up with fuel. I have replaced all 3 o rings on the mixture control valve , cleaned the carb parts good, but still setting the mixture contol value as lean as possible , I still cannot get smooth transition. After a minute of so of idiling it loads up with fuel so much that smoke and fuel blow out of muffler. At full throttle I get good response, a little rich, and at idle I have good response but cannot go from idle to full throttle unless I increase a little at a time. I cannot get the low side lean at all. Leaning the top to the point of engine stalling helps the transition some but then my top end is too lean. A new OS glow plug #8 was installed and fuel is good.