These really are hard to start!
 

Wow, these really are hard to start! My ZDZ Super 80 takes FOREVER to start. The first time it started pretty good, but was very rich and slowly killed the engine while idling before I leaned it out. Once I adjusted the low needle, it seems a lot harder to start. I've tried enrichening and leaning it, but it seems to be luck that gets it started. I advanced the timing a little tonight, but I won't run it until tomorrow. I tried the 5-5-1, and even tried more than 5's. Any ideas what adjustments to make to try starting it a little easier? Once it starts it runs awesome!

RE: These really are hard to start!
 

Since it's the weekend, I'll offer a couple of thoughts for you to consider.

ZDZ's need to be "wet" to start (when cold) or you're wasting your time and the most common issue I see with them is that you must have the choke closing all the way whether you use a servo or manual setup, make sure it's closing. Once you verify that, the 5-5-1 thing is a good place to start and you'll figure out what works for your engine as you get to know it better. I run mine dry at the end of each flying day, so it takes a bit more for the first start but the key for me is listening for the "snotty nose" sound from the engine when you flip it over with the throttle cracked and the choke closed. Once I hear that, it's choke off, ignition on and mine will usually go the next flip. If it's still a bit warm, no choke just turn on the ignition and mine usually go first flip. If it's been sitting for an hour or something, I give 'em one choke flip and they usually go the next flip. I always turn off the ignition when choking because if it fires with the choke closed, it'll be flooded and you're in for more flipping.

You mentioned it getting hard to start after setting needles; it is possible to set them just a tad lean when they are warm and then it's tough to get 'em going again when cold. Now we're not talking about a lot of difference in the low speed needle setting here either, once you're close, the width of a screwdriver blade may make the difference. So when you get close, be gentle on the final needle adjustments. If it's new as it seems, being a bit rich on the bottom will make for easier starting and it's definitely better than being too lean.

I wouldn't monkey with the timing as in my experience, if it's set correctly there's no advantage to changing that. If you advance it, it may run hotter and make it more difficult to start without any performance gain and if you retard it, you'll lose power although it might be a bit easier to start. Just leave it alone, 6.5 mm is used on a lot of the ZDZ's, but I can't remember if that Super uses 7 mm?

One last thought; if you have the Bing carb there were some issues with those and I think RCS is recommending and now selling the Super 80 with a Walbro carb.

RE: These really are hard to start!
 

Thanks Zeeb. I tried last night with choke on, full throttle 5 flips or so, then left the choke on, high idle, ignition on until it popped. Then just a couple flips and it started, but it had some residual heat in it. I'll mess around this weekend with it if my shoulder doesn't get too sore. I find if I richen the low end any, it runs way too rich at idle and won't stay running.

RE: These really are hard to start!
 

Choke closed, ignition on, until it pops. Usually under ten. Open choke, two or three flips until it starts.

RE: These really are hard to start!
 

What if it never pops, it just floods?

RE: These really are hard to start!
 

Something with the spark is bad. Bad plug, ignition, depleted battery, etc. Pull the plug, put it back in the cap and lay it against the cylinder. Rotate the prop and see if you have spark. I usually wear glove so I don't get zapped. Let us know what you get or don't get.

RE: These really are hard to start!
 

When I pull the plug it has Spark, just keeps flooding out. I did get it started this weekend, Tried the 551 and nothing so I turned it upside down in the stand and on the second flip it poped. I don't want to have to hang my plane upside down to start. Is there any other way to clear a flood?

RE: These really are hard to start!
 

How good is the spark? I've had spark on different engines before and they wouldn't start. I replaced the plug and they started right up. A guy at the field couldn't get his G62 to light. It had spark. I told him to replace the plug. He didn't believe me. I ran into town to get a plug. The engine fired right up with the new one. Try that first. It's the cheapest solution.

RE: These really are hard to start!
 

The spark is really strong.  I tried to start it today, wanted to try to fly a little on the holiday and nothing.  Pulled the plug and it is bone dry it doesn't want to suck fuel nows.  It goes from flooding to nothing...  ZDZ is never getting my money again.  Any help to get this thing started would help alot.  I have tied the 551 and nothing, I have done full chock and full throttle till it pops and it never pops.  the Ing battery is full charged, new spark plug.  100:1 AMS oil with perium fuel.  </p>

Thanks for any help</p>

RE: These really are hard to start!
 

Your using the wrong oil for one thing mix. ZDZ engines require nothing leaner than a 40:1 mix to help seal/protect the rotary valve. I wonder if that's the reason it's not drawing fuel properly.

RE: These really are hard to start!
 

hmm I may have to try that.  Every one told me to use the AMS oil after break in.  I will get some new fuel this week and some good oil and try it out.

RE: These really are hard to start!
 

Can't you mix Amsoil Dominator 40:1? That is my plan when Ifinally finish my bird.

RE: These really are hard to start!
 

I have Ams oil Saber and not sure if I can mix it at 40:1.  the bottle says 100:1 but I don't see why not.  any experts have any advice for this?

RE: These really are hard to start!
 

If the bottle says you can mix 40:1 yes, otherwise 100:1 oil is usually meant to be mixed at 100:1, and not to change the ratio.  same with all oils basically, unless they specify otherwise.

RE: These really are hard to start!
 

I believe Lins is right. Sabre is meant for 100:1. I would not mix Sabre at 40:1. Dominator, on the other hand, is meant for 50:1 premix or for injection systems, like snowmobiles. Since the difference between 50:1 and 40:1 is only 1/2 oz. per gallon, I can't see why Dominator can't be mixed at 40:1. Just my opinion, though.

RE: These really are hard to start!
 

Sabre is commonly mixed from 100:1 to 65:1, with a sweet spot crowd using 85:1

Dominator is commonly mixed from 50:1 to 25:1, with 40:1 being very popular.

RE: These really are hard to start!
 

I run my zdz 40 and zdz 50 on Dominator at 50 to 1. I also now use it in every engine I own, Zenoahs up to my 3w 150 inline with great results.
good luck
Paul

RE: These really are hard to start!
 

well I did get it started and ran well.  I am going to use this plane as my 3d trainer and when it dies a great death I will sell the engine and up grade to a da

RE: These really are hard to start!
 

hi everybody, i have a zdz 50 and it runs really bad around hover mode, if i lean it out to make it run good it wont start. it has a walbro carb. a friend of mine said he heard something about a diffrent carb but cant remember what it was about. any body know what i can do to make it run better. here is a link to a video of it so you can hear it run, just fast foward to 5:00 minuets imm lou its in the red and white qq yak (dont break my balls ive only been flyin about 1 year lol)

http://www.youtube.com/watch?v=XfT-aIAd-Do

RE: These really are hard to start!
 

Where do you have your carb vented to? Have you tried extending the vent back into the fuselage behind the 'cockpit'?

RE: These really are hard to start!
 

are you talking about the little hole in the pump cover??? its just in the cowl, i dont think i have anything on it.

RE: These really are hard to start!
 

Yup, that's what I'm referring to. Some people route an extension deep into the fuselage, but apparently that is more if you encounter surging. Never know, though.

RE: These really are hard to start!
 

First thing, when starting for the first time of the day have the choke on and wot and ign off. Flip till you see fuel drawn up the fuel line into the carb, then flip it 5 times. Then choke off, wot and ign off, flip 5 more times. The ign on, idle or 1-2 clicks above and ign on, should start right away (1 or 2 flips).
I would also turn the L needle out 1 1/2 turns out as a starting point, tweak it a bit till you get smooth transition of the throttle from idle to wot. You can tweak the needles a bit more once the engine gets broken in.
I used to use Amsoil Domminator 50:1 oil. I started off with 40:1 mix then switched to 50:1 mix, after about a dozen flights the motor (ZDZ 80 rv) started to lose power. Looking inside the spark plug hole, I noticed cylinder wall coating started to come off (this was an engine with many flights on it), sent in for repair. Was told it was more than likey a failure due to 50:1 mix, told to never run a mix thinner than 40:1 mix (36:1 for breakin). I recently switched oil to Yamaha 2 stroke oil on all my rc engines, I noticed a slight increase in rpm and more noticable was the drop in cyl temps. It was a very expensive repair bill, I will never run any thinner mix than 40:1 in any engine (especially in the ZDZ engines). I have two DL100's and the ZDZ 80 rv, I like both these engines.

RE: These really are hard to start!
 

thanks lins ill give it a try

RE: These really are hard to start!
 

I haven't had mine flying yet, waiting on batteries so I can't really help you too much. All I can say is check with RCS, I hear they have awesome service!

RE: These really are hard to start!
 

Umm.....

You're a bit behind the power curve here as RCS no longer exists and the product lines and service are now handled by TBM.

RE: These really are hard to start!
 

I wouldn't actually know, I've only bought a drill jig from them. I bought my engine elsewhere... Just trying to help him out.

RE: These really are hard to start!
 

Is there a good description online on REBUILDING a Walbro carb (NOT a "theory of operation")? I've pretty much determined that my 50NG will at least try to run if I squirt fuel into the carb - but won't run (or pop, or anything) otherwise.

Spark is good.

RE: These really are hard to start!
 

take your cowl off so you can see the fuel in the fuel line and rock the prop back and forth really hard and see if the fuel is moving in the line
let me know if it moves, you may have a pump problem.
and what do you have for a klunk? just a klunk or a filter. you dont need a filter, just put a filter on your jug

RE: These really are hard to start!
 

No cowl Lou - we screw all the gassers to my Nephew's wooden swing set :)

Pretty sure fuel was moving - but I'll double check. I pulled the carb apart a while back and put in a new diaphram (WT-76A IIRC)

RE: These really are hard to start!
 

If you're having carb problems not related to the rest of the fuel system, I suggest you consider changing out the carb for a WT-201(sorry I don't remember the suffix letter for sure but I'm thinking its a B). That's what RCS recommended and the newer 50's came with that carb. I changed mine out and it's worth doing IMHO.... [sm=thumbs_up.gif]

RE: These really are hard to start!
 

Zeeb, you're about the third one to recommend that particular carb. Have a (cheap) source? :)

RE: These really are hard to start!
 

Sorry I don't, mine came from RCS.

Word has it that this carb is what DA uses on the 50R, but for some reason still not clear to me they take out the model number on their carbs with an etching pencil deal....[sm=confused.gif]

Not sure if DA has any better pricing on replacement parts than RCS did, but word has it that TBM has been real good to work with on parts and IIRC Mike Dooley is doing the warranty/service thing for those lines RCS carried. I've used TBM before and have nothing bad to say about those folks other than the ground shipping from Florida to where I live in Utah takes 10 days. Maybe give them a call????