Barry-RCU

OK, so I got my new ZDZ 40 after hearing all the good stuff about these engines. Why is it so hard to start? By the time I get it started my arm is to tired to operate the radio. The instructions say that the needles are factory adjusted so you shouldn't need to touch them, but if you do mess with them you should start at 1 1/2 turns out. Well I didn't touch them but when I finally got it started the first time it ran very rough and had little throttle response. So I decided to see where they were set from the factory and both were out about 3 turns. I adjusted them to the 1 1/2 turns and had better luck as far as how it runs (runs pretty good) but still very hard to start hot or cold. This is my first gas engine so I am doing what the instructions say; Ingition on, choke on, throttle full, flip till it tries to start; at that point choke off, less than 1/4 throttle, should start right up. Well it doesn't work that way. It has fuel in the line (or appears to) and a fresh 1100mah battery. The fuel line is only about 6" total length. I am aware of the auto off feature on the ignition and it doesn't sit still that long. Once started it seems to run fine, just too hard to get going. Any suggestions?

kevin mcgrath

My Feedback: (1)

Which brand of ignition came with it? you say you got it new......NIB from another owner,from Europe,or RCS?

Johnny_Rebel

try just richening the low end slightly - when my bme44 gives me a hard time that seems to work- just an 1/8th of a turn or so.

Barry-RCU

Kevin- NIB from a hobby shop. I assume he is legally selling them as he had other ZDZ engines and I saw his invoice from RCS. Falkon Ingition.
Johnny- I tried many different needle settings. It originally was richer.

EdwardB

My Feedback: (6)

I have the same engine, and also agree it can be hard to start. My best luck starting was by priming directly into the carb, because if you open the needles enough to get it good and "wet" then it's really rich once it starts running. There have been several posts about soldering shut the small hole in the choke plate. Apparently this solves the problem. I haven't tried it yet, because I'm working on a couple of different projects right now, but maybe this is what you need to do.

Diablo-RCU

My Feedback: (1)

Run a 3 line tank so that the line to the carb always stays full of fuel. That way, a lot of choking and flipping is not required to pull fuel from the tank to the carb. Once fuel is at the carb, set the throttle to idle, choke on, ignition on, flip t'il it pops. Turn choke off, throttle at idle, ignition on, flip t'il it runs (usually 3-5 flips).

Mixture adjustment - once engine is warm, set the low end first for quick acceleration from idle to about half throttle and clean running (not a lot of burbling) in that throttle range. Next set the high end mixture at full throttle with a tach - lean it until you get max rpm, then richen the needle so it drops by about 100 rpm. Test fly it. If it burbles consistently in a certain throttle range it is rich and requires a little leaning.

Also, the low end needle changes the mixture over the whole throttle range. The high end needle only effects the mixture at about half throttle to full. That's why you adjust the low end needle first. This is not like a glow engine.

kevin mcgrath

My Feedback: (1)

Diablo has touched it all......Only thing I can add is that the fuel line length that you mentioned is not significant nor is the tank position as we are used to with most glow engines due to the pump carb on almost all gassers.
Id work on your starting technique and if you have no more success talk to RCS before making any mods to the engine and see what they want to do.They are normally first class for service IMO.
The reason I asked about the engine source was to make sure you had the latest ignition as there were some problems with earlier issue,but all sounds OK if you have the falkon,which as far as I know has been bullet proof......
Please make sure to tell us what happens ,good or bad.....

Good luck...

rthorne

My Feedback: (29)

I had the same problem with my ZDZ-40. I when I broke the engine in I had the cowl off of my Sig Sukhoi.

I noticed it took for ever to see the fuel actually make it to the carberator. Once the fuel made it to the carb it started right up.

I spoke with Mike at RC Showcase. He asked me if I had a pin hole in the butterfly cover on the choke, it did. He suggested that I solder the pin hole to totally seal the carb when the choke is on.

This conversation took place after my Sig was destroyed on the first flight (sig replaced the plane by the way).

Anyways, the hole is now soldered and will be going on an RC American Cap 232 very soon. I'm hoping this will solve the problem.

Just a thought.

JohnVH

My Feedback: (38)

I dont know for sure if its got the same ignition as my g62, but, check the gap on the cdi box to the magnets, mine wouldnt start, adjusted it, then it started right up!

Barry-RCU

Problem solved. As it turns out the screws holding the hall sensor bracket to the engine were not very tight (as in no screwdriver required) and the sensor was all the way to one side of the adjustment (11 mm instead of the 7mm factory spec) . After setting the timing as per factory specs everything is just fine. I also soldered the choke plate hole closed. Two flips choke on, ignition off and fuel is in the carb. Two more flips choke on ingnition on and it burps. Choke off ignition on 1/8 throttle started right up. Re adjusted the carb settings and ran on the ground for a while. Shut off for about 5 minutes and it started on the first flip. Isn't life good!
Thanks very much to all of you who replied. Now it's off to the field. I just hope I can fly with this ice pack on my arm.

JohnVH

My Feedback: (38)

Trust me, I know what your talking about!!!!!!!!!!!

kevin mcgrath

My Feedback: (1)

Been meaning to say to all who are wearing out their arms with balky starting electronic ignition gassers,that the speed you crank at has no bearing unlike the magneto equipped engines,so save your effort if you have a starting problem and crank it only hard enough to get it past compression and get your hand out of the way....

Forgues Research

My Feedback: (7)

It took me exactly 2 minutes to realize why the fuel wasn't being sucked up on my test stand. In the choke buterfly, plug the little hole completely. Once this is done, I leave the throttle at idle, with full choke and ignition on, and she fires after 3 to 4 flips, open choke a and 2 to 3 flips the engine is running.

Roger

ACM Rep....

Team ACM
Fiber Optic Servo Extensions
Forgues Propellers
Multiplex Dealer
http://www.aerografixs.com
Model-Scan Frequency Analyzer

CAPtain232

My Feedback: (40)

I have to agree and disagree with Kevin.

In my opinion, you should flip the prop as fast as you can. The momentum that you have created will get your hand out of the way. Otherwise his comments are accurate.

Jeff

captinjohn

How is one certain the solder that is used to block-off hole on choke plate is not going to come loose and damage engine? Thanks, CaptinJohn

Forgues Research

My Feedback: (7)

Good soldering is the answer,
Roger
ACM Rep....

Team ACM
Fiber Optic Servo Extensions
Forgues Propellers
Multiplex Dealer
http://www.aerografixs.com
Model-Scan Frequency Analyzer

rthorne

My Feedback: (29)

It appears that the butterfly is brass. Solder will adhere to it very easily and won't go anywhere.

I used a 40 watt iron from Radioshack and the solder flowed in, around and over the hole in a matter of seconds.

There won't be any appreciable stress on the solder so it will stay put.

Barry-RCU

Soldering the hole wasn't an issue in this case. I confirmed the timing issue first. Fuel draw wasn't that bad but it did improve after soldering the hole.

Diablo-RCU

My Feedback: (1)

I soldered up the hole for a friend. Just took some thin brass shim stock, cut it with scissors to fit over the hole, sanded the choke plate near the hole to clean it, wiped it with a paper towel, heat the choke plate until the solder flows well and wets the metal, remove the heat.