ZDZ80 SUPER
#1
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Join Date: Jun 2002
Location: YUMA,
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MY ZDZ 80 IS HARD TO START I HAVE DONE LIKE THE MANLE TOLD ME TO DO STILL HARD TO START O AND THIS IS A NEW ZDZ 80 BUT WHEN I GET IT TO START THIS ZDZ IS A BAD ASS ENGINE THIS THING RUNS GREAT STILL ON 32-1 MIX ABOUT 3 GALS IT WAS STARTING LIKE A TOP BUT NOW IT IS NOT ANY HELP OUT THERE THANKS
#9
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Join Date: Dec 2006
Location: Poplar Bluff,
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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.
Mr Gerald D Robison
Poplar Bluff Mo.
#10
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I ended up installing a RCEXL ignition on my ZDZ 80, and set the timing to 28 DEG. That was three years ago, and havent looked back. Runs perfect, and lots of power. Still running the original sparkplug in it. NGK
#11

Join Date: Oct 2005
Location: Yellowknife,
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Once mine was broken in and nicely tuned, it started no problem.
Edit: Even though it is a great running and powerful engine, NOW, I would not go the ZDZ route again. Not after all the problems getting her started while she was new and breaking in.
Edit: Even though it is a great running and powerful engine, NOW, I would not go the ZDZ route again. Not after all the problems getting her started while she was new and breaking in.
#12
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Up date on the ZDZ super 80 RV. Been flying this engine on a 33% Yak 54 now for 4 years. After figuring out the starting techneek, it has given me very good service. That was after replacing the stock ignition with a RCEXL ignition. The only issue I have with this engine is the cylinder is wearing at the top of the piston stroke. This is one of the black cylinders that is not susposed to wear. The piston ring was also worn quite a bit, and I replaced it with a new one. Now for the interesting part. Not thinking about it at the time, the cylinder never wore any, right where the rang end gap came to. The old ring simply followed the naterial wear pattern of the cylinder. The brand new piston ring when installed had less end gap, and rode up on the old endgap part of the cylinder. This effectley caused the piston ring to be unseated at the very top of the compresion stroke, dumping all the compresion at very critical time in the compresion cycle. For the first time, I had to use a electric starter to get it running. The new ring broke in enough after about 5 minuts of running to hand start after that.
Just thaught I would pass along this information, might be helpful to some one out there. These newer cylinders are not susposed to be wearing like that, but mine has. I have three China made engines that have ran and ran and ran, with no cylinder wear at all. All use the same gas oil mix, 32 to one.
Cropduster48
Just thaught I would pass along this information, might be helpful to some one out there. These newer cylinders are not susposed to be wearing like that, but mine has. I have three China made engines that have ran and ran and ran, with no cylinder wear at all. All use the same gas oil mix, 32 to one.
Cropduster48