ZDZ40 Newbie Help
 

I bought a GP 1/3 scale Pitts that has a ZDZ 40 RV-L in it. The engine is side exhaust with a Pitts style muffler that, from the pictures, is probably the Supersonic unit on the R/C showcase site
http://www.rcshowcase.com/images/acc...0_rv_front.jpg

Unfortunately, I have no manual for the motor. I downloaded a 5 page manual from the zdz.cz website, but it's not any help as far a setting up the electrical system. While I've been in the hobby thirty years and have had dozens of two and four strokes, this is my first gasser. I have several questions:

1. This engine has a Falkon ignition module and Bing carburetor. Carb is easy thanks to the FAQ on the RCshowcase website, but how do I hook up the ignition module? It has a three wire Futaba or hitec type plug on it. From what I've read, it should just go to a battery pack. What size would the battery be, and what is the third wire for?

2. The builder has a small switch mounted on the firewall, like this: http://www3.towerhobbies.com/cgi-bin...?&I=LXJ776&P=0
A servo shoves a pushrod into it. I'm assuming this is a kill switch like a lawnmower or weed eater has, or would it be inline with the battery pack?. The wires are not attached to anything, and I didn't see any obvious attachment points on the engine. Where should I attach them?

3. There are two fuel lines going out the fuel tank, both terminating outside the body with something like a fuel dot, except they have a thumbscrew that threads into the openings, and are sealed with an O-Ring. The fill line on the clunk has a tee that goes to the carb, while the vent line has no engine or crankcase connection, other than the well sealed cap. Do I just remove the vent cover before running, or is there some line missing from the carb that would pressurize the tank like a chainsaw uses to get fuel to the carb?

4. I'm assuming the fitting on the muffler is for smoke. If so, I was going to get the Megasmoke Plus from RCshowcase. I think I can eliminate the extra servo for the kill switch if I go that route. Am I headed down the right track, or should I get the unit w/o the switch and stick with what I have? Reliability and safety are more important than a couple bucks to me. How well does this unit make smoke?

Thanks for any and all help.

RE: ZDZ40 Newbie Help
 

Hello,
You'll probably get a dozen or more answers to your questions but I'll try to help as I have a few ZDZ motors as well as DA and they are all about the same in functionality.

The ignition module of course has the one wire for the timing sensor which must be set correctly for good running and easy starts. (try starting the set point at about 3-4mm btdc). The secong goes to the spark plug. Be sure that there are no cuts or holes in this wire or else you will get a spark jump and very erratic running. Sometimes it won't run at all. The third wire on the other side of the ignition module is the one which basically goes to the battery. Normally, they all come with a 3 wire JR plug but it could differ. Mainly it must have the + and - for the battery.

ZDZ ignition modules turn off by themselves if the motor is not turned over for about 1 minute. Something to remember! You could plug the battery and the ign directly together but that would be dumb. So, simply insert a switch between the battery and the ign module and mount wherever it is easy to turn off and on.
If you want to run a kill switch (highly advisable) just place the internally mounted kill switch between the battery and the 1st switch. Plug the kill switch into a servo and this servo into the reciever and assign a channel /radio switch for that purpose. If you leave the battery in the plane while recharging, ok for NC or NiHD, then be sure to have a charge lead on the switch connected to the battery. If the Ign module will handle Lipos then I highly recommend you remove them from the plane while charging. ZDZ has differnet ign modules- the older ones will not handle Lipos. As a general rule, a 1200mAh battery gives me more than enough time for a full day of flying- sometimes a complete weekend if I've only flown 3 or 4 times each day. Actually, an 800mAh would probably be enough. One other thing- be sure to use loctite on that damn set screw for the sparkplug cap! It will work loose and the engine could quit as the mort inoppotune time! Don't ask how I know that [:@] !!

Yes, it looks like that nipple on the photo is for smoke. I don't use these types of mufflers(?) over here in Germany- way, way, too loud. Also, I never have used presure in any of my 'gassers'. The carb will pull the gas into itself via the membrane. If the membrane is not defect or worn, it shouold do fine. I also don't use a 'T' fitting. I use a 3 line system- 1 for fill, 1 to the carb, and the third for overfill or draining after the day's flight. I plug the overfill line so I don't get spills in my car while transporting and leave it open while flying. It will run with it closed but you need to set your needle valves accordingly. Try either way to get best performance. Just don't let it run lean! A little on the rich side is much better than too lean!

If you use the switch setup as shown in the Tower ad, you'll have to modify those blade ends to fit the connection to the ign module. Whatever method you choose, be sure your switches are good quality as the vibration will eventually cause intermittent problems with them. But I'm sure you're aware of that!

Should this attempt of an explanation not be clear to you, I can send some photos of a similar setup that I talk about here.

Good Luck! PS- are you sure that 40 is enough power for the Pitts?

RE: ZDZ40 Newbie Help
 

"Hello,
You'll probably get a dozen or more answers to your questions but I'll try to help as I have a few ZDZ motors as well as DA and they are all about the same in functionality."

Any and all advice appreciated. Thanks for the quick answer. You confirmed most of my assumptions. The plane has obviously been flown before, but the engine supposedly has never been run. I bought the combo from a club member selling off the estate of another club member for his widow. I'm told he never flew the motor, but two of the holes in the hub are stripped out. The motor was mounted, with a 20*10 "Bambula" prop, but other than that he hadn't done much to finish hooking it up. The throttle linkage is adapted from the previous motor, and the wires to the kill switch are simply cut off 3 inches from the switch. I was hoping the third wire in the module would allow it to plug into the throttle channel for a kill function, but that is not the case. You mentioned you used a 3 line system, which is my norm also. I'll probably make that change and get rid of the T. I take it no check valve is needed either way?

I'll get a new hub when I order the smoke system. I'm mainly looking here to make sure I get everything I need, and to make sure I do it right the first time. I've learned from other forums about a lot of things I should do to the Pitts to keep it from falling apart in mid-air. The motor is new territory for me, so I'd like to make sure I don't build in any headaches. As far as power goes, book calls for OS 160 two stroke or US41 gas. I think the ZDZ has more power than the US, so it should fly well. I'm not looking to 3D this plane, I've got other stuff for that.