ZDZ 50NG Kicked my butt today

[JeeUm]

Ok, so I know a fair amount about running gas motors. I'm no guru but can usually solve most problems. This one has got me scratching my head and icing down my right arm after flipping for 2 hours.

It acts like it's burning off it's prime. I've tried every combination of needle settings and ignition timing settings.

It starts and pops every single time, will run for about 2 seconds with the choke on and I even had it running for about 2 minutes at one point.

The only thing I haven't done yet is tear down the carb and check the screen. I'm keeping my fingers crossed that is the problem, but I doubt it.

I've gone back to factory on the needles, and even up to 1/2 turn either side.

Fuel is 32:1 93 octane

Any of you ZDZ guys have any ideas? I know it sound like it's not pulling fuel so I'm gonna tear down the fuel system but I don't think thats it as evidenced by the puddle of gas on my driveway.

[Gary Powers]

Sounds like my 60, JeeUm! We could not get it started. Sent it back and they could find nothing wrong with it. Got it back, remounted it and still could not get it started.

Finally, a friend walked up, shot a squirt of brake cleaner into the carb and VROOM, scared the hell out of me on next flip. I now have about 2 1/2 gallons through it and it is still a bit difficult to start on the first flight of each day. Hard to get wet, I guess. However, after that the 5-5-1 sequence kicks it off easily and everytime. Great power! I have it on a 18+ pound 30% SD Yak and it is just a delight to fly, even very rich and with a small prop (22 X 10). Should finish break-in next weekend and will be ready for the El Paso IMAC at the end of the month.

Buy a can of brake cleaner and save your shoulder. I only had to use it twice, but it was well worth it.

Gary
El Paso

[3ddd]

leeum does it have fiber reed plates on that engine.i know when a 3w 50 does this it is usually a reed is not sealing or is cracked.it will not pump this away because it still takes crankcase pressure to make a carb pump.when the reeds leak it all goes out the carb.hope this helps ya.oh check it for vacum leaks also

[Fudman]

a flying buddy had a manual to the ZDZ starting technique If I remember right he flips it 10 times with choke on and ignition off then turns the ignition on and it normal starting from there, from what I understand ZDZ's have a hard time getting fuel first run of the day, but when he started using this method he didn't have a problem. (I think he got the instructions from a thread on RCU)

thats just what I remember, who knows might work.

[sproose_moose]

I have 2 a 50 and an 80. I have choke servos on both. On the 50 close the choke start flippin, when it pops I can almost always flip off the choke and it'll keep running. With the 80 i can rarely keep it running by flipping off the choke. So I have to flip it with the choke open and throttle just off idle about 4 more times. They take a lot of flips the first flight and seem to flood easily. Also each engine has a unique starting sequence that works best but if you can find it your set, it will start the same way every time.

[Boulder]

On my ZDZ-80 it usually takes full throttle, choke on, ignition off rotate prop until the carb is wet, throttle down to 1/8, ignition on and it usually pops after about 5 flips. Turn choke off, throttle to 1/4 and 3 or 4 flips it usually starts.

If I don't follow this procedure it can take 20 to 30 flips.

[JeeUm]

Just pulled the carb apart and its fine. Clean as a whistle. It also has the better carb which I understand is the WT201.

I tried every combination of flipping that I could think of and all it would do is pop, run for a sec or 2 with the choke on and quit.

I'm stumped.

[aerofundan]

i have the same problem on mine, if you have the Walbro 76A carb, its the defect one, i'm going to have to order a new carb for mine, which fixes all the starting/choke/transition problems, i was able to fly mine for a while with starting problems, but now its almost close to impossible to run.. here is a vid of mine

http://www.aerofun3d.com/videos/PAEdge540.wmv

[JeeUm]

Daniel, I actually just read your thread on another website which clued me into the carb, luckily it looks like I've got the better one. If it's at all possible, could you check your timing and let me know where you've got it? Just measure from the edge of the pickup mount to the central web support on the bottom of the motor.

Mine has a mechanical choke and I thought that maybe if I could have caught it a couple times it might have kept running. I'll have to try that tomorrow when JayB stops byl.

[airriley]

Ahh the dreaded ZDZ shoulder. I have a 100ng that has made me curse a few times. They can be a bear to start and not all may start exactly alike. Once mine would flood there was nothing you could do to clear it without any tools. And if it did flood you could flip it till the cows came homem without any sign of life. (Don't forget about the automatic timer on the ignition, it will cut off if not flipped withing the last 30 seconds). The only way I could clear it was to either defuel it, or shut the low end needle all the way. It would start popping a few flips after that. What I finally did that ended up working for me is to move the throttle choke servo to a knob or a slider instead of a switch. Choke on, full throttle, ignition on - flip until it pops. First pop reduce throttle 1/8 or so, and set choke to 1/2 open. Flip until it starts and immediately but slowly open choke. It's the only method so far that has saved my sanity.
Hope it works for you.

[JeeUm]

Hmm, 1/2 choke. Might have to try that. Mine pops every single flip with the choke on, then will run for a couple seconds like most motors do. I think maybe if I can catch it with the choke I might keep it running.

The one time I did get it going it spun the Vess up with authority.

[aerofundan]

Jim, I adjusted the timing also, and it was perfect out of the box, I don't remember right now the measurement, but its where it should be, I have to tell you, its been like this always, really hard to start, most of the time, the solution was to use a starter, but now its to the point that even with the starter it wont start, it just won't draw fuel from the carb, you can choke it all you want and its impossible, only way is if you manually shoot fuel into the carb with a fuel pump, at that point the engine starts and starts drawing fuel......

I already have about 4 weeks straight having a sore arm from this engine i hope the new carb fixes it... if not i'll sell it and a buy a chinese 50cc motor that will probably solve my problem faster