ZDZ-80 Rocks, hard to start  
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ZDZ-80 Rocks, hard to start - 7/8/2003 5:14:28 AM   
jelaird



Posts: 461
Joined: 1/12/2002
From: Gilbert, AZ, USA
Status: offline 		I can't express how happy I am with my ZDZ-80 vertical performance with just a Bambula 26x8 prop on a H9 Sukhoi. It kicks royal booty. Up-lines are unlimited and always get some good comments from pals. But starting this baby is getting me frustrated. I get a pop with choke after 3 flips with any throttle setting between 50% and 10%, but after opening the choke, it takes 5 flips before I start getting individual pops like it is going to take but it never does. As a matter of necessity, I literally have to flip harder and move the throttle up to 50% before I get it to light off (15 flips min.). After the first flight and "warm" it takes about 5 flips before I get the idea that it needs choke on again, after that pop, it takes about 10 killer flips unchoked. I looked at the RCShowcase web site and went for the timing procedure. With my sensor in the stock position against the end of bracket's slot travel, I measured 6mm between magnet and sensor, compared to the 7mm needed. I gladly advanced the timing by 1 mm and next time out I got remarkable starts. 2 flips to pop from cold with choke, 3 flips without choke. The rest of the day it started on the first flip with no choke (excellent for me). Too bad, my vertical performance was lost and only marginal at best. I went 1/8th leaner on the high needle with no improvement. I decided to return the sensor to the stock setting next time out just to make sure it wasn't an anomaly and sure enough...top end was back but hard starts were the order of the day. With 20 flights and 4 gallons through it, my needles have wound up to 1/2 turn out on the low and 1 turn out on the high. Does any body think I need to go back through the entire mixture procedure to get my top end back at the easy-start timing? Should my ignition module be sent in? Maybe my 26x8 break-in prop needs to come off and replaced with the 26-10. I will take the cowl off and do up some RPM numbers with needle settings next weekend but until then, please reply with any advice you have.
Thx

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Jack
Chaos, panic, & disorder - my work here is done.
       Post #: 1

ZDZ-80 Rocks, hard to start - 7/8/2003 6:56:22 AM   
lennyk


 

Posts: 567
Joined: 12/8/2001
From: Port of Spain, FL, USA
Status: offline 		I also have been trying to figure out a starting procedure with mine.

What you can do is if you find that it will pop reliably when choked after 3 flips then it would probably start on the 3rd flip after 2 flips with the choke.

So you can try flipping it with the choke on but ignition off for 2 flips then switching on the ignition and taking off the choke and trying to flip it.
I find that when it pops with the choke on it seems to empty all the gas from the engine and I still have to flip a good few times without the choke on.

Starting after the initial first start could be a bit tricky so it might be safer to not choke it too much otherwise it might flood as the diaphragm would already have fuel in it.

(in reply to jelaird)
       Post #: 2

ZDZ-80 Rocks, hard to start - 7/8/2003 7:09:56 AM   
cygnet


 

Posts: 297
Joined: 1/6/2002
From: Calgary Alberta, AB, CANADA
Status: online 		I can't belive that it runs a 1/2 turns on low both my 80's are at 2 1/4 on low and 1 to 1 1/4 on high I bet that you are hard to start beacuse you are lean on low Just my .02

(in reply to jelaird)
       Post #: 3

ZDZ-80 Rocks, hard to start - 7/8/2003 7:44:33 AM   
lennyk


 

Posts: 567
Joined: 12/8/2001
From: Port of Spain, FL, USA
Status: offline 		Mine is new with Walbro carb,
both needles are about 1 1/4, still rich and burbles

(in reply to jelaird)
       Post #: 4

jelaird - 7/8/2003 8:17:43 AM   
3wExtra


 

Posts: 524
Joined: 12/30/2002
From: seattle, WA, USA
Status: offline 		is your carb a bing? I am getting very frustrated with both the engine and Showcase's support, I have put at least 10 calls to these guys and nothing. I can not get it to stop burbling neither, it is hard to start if timing is set by instructions, if I set the timing to be easier to start, then it does not my plane...

(in reply to jelaird)
       Post #: 5

ZDZ-80 Rocks, hard to start - 7/8/2003 8:36:23 AM   
jelaird



Posts: 461
Joined: 1/12/2002
From: Gilbert, AZ, USA
Status: offline 		I forgot to mention, mine is the new Walbrough carb model purchased this year. The low end needle is set to where 1/8th leaner it will die on the runway with throttle advancement. Yet I still have some major burbbling during transition around 25-30% throttle. The prop would freewheel during downlines until I leaned it this far causing some definite "pucker" on manuever exits. I found the spark gap at .029", closed it to .022" as well. No effect. I just had a thought, is it possible for the sensor to be somewhat polar in it's directional sensitivity. Mine looks perpendicular to the arc of the hub. Maybe it could be out of square.....

_____________________________

Jack
Chaos, panic, & disorder - my work here is done.

(in reply to jelaird)
       Post #: 6

ZDZ-80 Rocks, hard to start - 7/8/2003 8:43:02 AM   
beachhangar



Posts: 74
Joined: 3/3/2003
From: Carlsbad, CA, USA
Status: offline 		Similar experience as Lennyk.

Cold - 2 or 3 flips choked at 50% throttle. Then choke off and it will start on next flip with throttle at about 15%. If it should pop while choked it usually takes another 6-10 flips to get it to catch.
Warm - ignition on and usually 1st flip. Bing carburetor.

Timing is at end of travel and that appears to be about 6mm between center of slug and center of sensor.
I get about 5800 (close to sea level) on a Mejzlik 24-12x3 with a KS can in the fuselage. Another club member gets 6300 on Mejzlik 24-12x3 with RCS can in fuselage.

mike

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Aerobats & warbirds

(in reply to jelaird)
       Post #: 7

ZDZ-80 Rocks, hard to start - 7/8/2003 10:21:55 AM   
cygnet


 

Posts: 297
Joined: 1/6/2002
From: Calgary Alberta, AB, CANADA
Status: online 		Go to the ZDZ web site they have a fix for the rich running on a bing carb the web site is very good and gives pictures to take you through the procedure. I have the bing carb on both of my 80's and they both run great. Try this for starting, power off, choke closed, throttle wide open, six flips, throttle closed to idle, choke open, power ON,should go first flip

(in reply to jelaird)
       Post #: 8

starting - 7/8/2003 10:12:57 PM   
dirtybird


 

Posts: 3084
Joined: 1/25/2002
From: Mesa, AZ, USA
Status: offline 		A Miller reduction system on a Sullivan starter running on 24 volts solves the starting problem for me. It also keeps my hands out of the prop.

(in reply to jelaird)
       Post #: 9

just got - 7/8/2003 10:32:30 PM   
3wExtra


 

Posts: 524
Joined: 12/30/2002
From: seattle, WA, USA
Status: offline 		a new ignition from RCshowcase. lets see what happens.

(in reply to jelaird)
       Post #: 10

ZDZ-80 Rocks, hard to start - 7/9/2003 6:31:04 AM   
JohnVH



Posts: 14763
Joined: 12/5/2001
From: Lynden, WA, USA
Status: offline 		Try this, worked awesome on mine

Choke on, half throttle, ignition off. 2 flips

Choke off, throttle to idle, ignition one, 1 flip start


I LOVE MY 80 for reliability and power!

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---AIR VH---*FURY FLYER* www.3DFoamy.com

(in reply to jelaird)
       Post #: 11

ZDZ-80 Rocks, hard to start - 7/9/2003 8:44:43 AM   
jelaird



Posts: 461
Joined: 1/12/2002
From: Gilbert, AZ, USA
Status: offline 		John, just 3 questions...
1. Is yours the Walbrough carb model?
2. Do you do the same procedure after warm too?
3. Is your tank mounted up front in the Su-31 like mine?

Just wondering, your method sounds tempting before I mess with the timing again.

_____________________________

Jack
Chaos, panic, & disorder - my work here is done.

(in reply to jelaird)
       Post #: 12

ZDZ-80 Rocks, hard to start - 7/9/2003 8:47:11 AM   
JohnVH



Posts: 14763
Joined: 12/5/2001
From: Lynden, WA, USA
Status: offline 		1. I think mine has the Bing on it, not 100% sure, but I have pics of the engine if you can tell from that.

2. depends, unless I just got done running it, sometimes it will fire first flip with no choke, but warm I do choke on, ignition off, half throttle, one flip. Choke off, throttle idle, ignition on, one flip starts

3. Tank is in stock position

Try it! FWIW, I didnt move the sensor from the factory, but I did measure it and it was right on the money.

_____________________________

---AIR VH---*FURY FLYER* www.3DFoamy.com

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       Post #: 13

ZDZ-80 Rocks, hard to start - 7/10/2003 7:10:36 AM   
Forgues Research



Posts: 3414
Joined: 12/15/2001
From: Glen Robertson, ON, CANADA
Status: offline 		A friend showed me the way to go to start the ZDZ engines easily without walking down the Chiropractor afterwards.

Full choke, full throttle, ignition off. Don't flip over compression. Simply rock the prop back and forth, bouncing it on compression about 10 times.

Romove choke, throttle to high idle, ignition on, flip start.

Give it try.

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Evo Engines
http://forgues-research.com

(in reply to jelaird)
       Post #: 14

ZDZ-80 Rocks, hard to start - 7/10/2003 7:15:48 AM   
lennyk


 

Posts: 567
Joined: 12/8/2001
From: Port of Spain, FL, USA
Status: offline 		How easy is it to flood an inverted engine doing this method ?

(in reply to jelaird)
       Post #: 15

ZDZ-80 Rocks, hard to start - 7/10/2003 7:17:23 AM   
Forgues Research



Posts: 3414
Joined: 12/15/2001
From: Glen Robertson, ON, CANADA
Status: offline 		[QUOTE]Originally posted by lennyk
How easy is it to flood an inverted engine doing this method ? [/QUOTE]

Well, mine is a boxer, but my friends' is a single inverted and he has never had a problem using this method at least in my presence.

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Evo Engines
http://forgues-research.com

(in reply to jelaird)
       Post #: 16