ZDZ 80 single issues
11-02-2002, 03:45 AM
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ZDZ 80 single issues
I have the ZDZ 80 single which only has about 4 gallons through it and I'm having problems with it staying at a high idle. On my transmitter I have set up a high and low idle switch. The motor will run for about 30 seconds on high idle and then it will act like I had switched it to low idle. I have gone as far as to putting a Walbro carb to see if this is the problem but still no success. I had three deadsticks today and each time I had a very high idle on the ground. Other than this problem the motor pulls my 26lb sukhoi with no problems at all. I have tweaked with the low end needle setting and got the motor to run awsome for a minute or so on the ground but as soon as I get airborne and get some altitude the idle drops way down. HELP!!!!!!!! I have no ideal to whats going on. Any help would be appreciated.
11-02-2002, 04:21 AM
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ZDZ 80 single issues
Hmmm...I wonder if it's flooding out.
You might be getting some weird suction effect around your carb venturi once you're in the air, causing a super rich condition at idle. I'd say a velocity stack would be worth a try, but that motor has a rear mounted carb doesn't it ?
Usually if it runs great on the ground and acts goofy in the air, it's an air/fuel metering problem revolving around too little or too much air pressure around the carb venturi.
You might be getting some weird suction effect around your carb venturi once you're in the air, causing a super rich condition at idle. I'd say a velocity stack would be worth a try, but that motor has a rear mounted carb doesn't it ?
Usually if it runs great on the ground and acts goofy in the air, it's an air/fuel metering problem revolving around too little or too much air pressure around the carb venturi.
11-02-2002, 05:01 AM
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ZDZ 80 single issues
Yes the carb is in the rear and I have a hole cut out of the bottom of the motor box so excess fuel can escape. I'm wondering if I have too much air getting to the carb.
11-02-2002, 06:32 AM
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ZDZ 80 single issues
From my experience with this engine it is a set it and forget it kind of engine. I would get back to basics and start by checking your sensor position and high and low needles. If these are OK..look at your fuel system to make sure you don't have any obstructions or loose fittings. It is a good practice to put some holes in your motor box so the carb can breath. I usually put one or two 1/2" holes in the sides and bottom of the box. The top has a cover that is screwed on. Getting back to the engine make sure that your throttle butterfly is turning the right way and that everything is tight. I usually set my low needle first, then peak the rpm and back the high needle off a little on the rich side. Once this is done you don't really need to fool with it. I wouldn't stress myself out over it. If you still can't get it to work right box it up and send it back to RC Showcase. For a small fee they will get it running good as new.
