cropduster48

My zdz 80 rv-j sounds all the world to be having ignition problems. Also having some kickback problems while starting. And yes, the ignition mod is set corectly. Its a new engine, and no I havent tried changing the sparkplug yet. Low needle set at 1-7/8. Forgot what the high needle is set at, but it is leaned out just enough to stop the 4 cycling at full power. 93 octane, 32 to one Lawn Boy oil. No air leaks in fuel syatem. Engine starts pretty easly, idels fairly well. I am running the battery power through a miriacle switch, reducing the voltage from 8 volts down to 6 volts. Could this be my problem. I have heard that miracle switches don`t work well on ignition systems. The exact problem is this. Random miss fire along with a backfire through the muffler followed by a very rough running engine for about 10 seconds, and then sudenly starts running properly again. This problem while active stays present even while reducing power all the way down to idel. There seems to be nothing loose in the wiring. Using standard recomended prop for this engine. Engine has non restrive cooling air, but is trying to run very hot. Max temp I have seen is 320 F. The engine has not been stuck, is very quite, and has good compresion. This engine sounds like it is running to much ignition lead, but the pickup senser is set corectly. I have flown my Yak 54 two times with this engine, but landed becaus of the rough running engine after take off. When it decides to run corectly, it has lots of power. I have a lot of experence with highperformance two cyle engines, so any input would be helpful.
Mr Gerald D Robison
Poplar Bluff Mo.