Recently a friend of mine had a ZDZ 80 overheat and lock up after only about 15 flights. He had followed the break-in procedures as provided by the mfg. Up until that point he really liked the engine. I have been thinking about getting one of the same engines myself but now I'm a little hesitant.

I wanted to know what other people thought about the engine and if anyone else had had a problem like this with the same engine.

There have been no reports of inherent overheating problems with any of the ZDZ engines.Your friends breakin procedure,the ratio ,brand,and type of oil used,high end needle setting (too lean?),air flow through any cowling involved,etc etc......are more likely at fault,IMO.

That's what warranties are for. Nobody builds the perfect engine every time. After your buddy sends the engine in for repair, let us know how they resolve it. RCShowcase is very good at taking care of their customers.

Its the first time I hear of a problem of this nature with ZDZ, with all the success of ZDZ, I don't think its a point of being hesitant in the purchase.

Don't hesitate. I just got back from the field. I have a zdz80 in m GP 33% 330L. Great flying plane/engine. Its still being broke in, its had 5 flights plus some test stand run time.

I would guess one of two things. It in fact has a defect which the warranty should cover or two it over heated do to inadequate cooling which the warranty won't cover.

Lets hope its the first. If it is RCshowcase will come through.

A friend of mine up North had the same thiing happen to his, and he's an experienced auto mechanic and flown for a long time. ZDZ 80 single, after 3 hours it dropped the chrome. Probably a dud but I'd still buy one.

I haven't been able to raise the RC Showcase website all day.

Me too but I got thru tonite.

The ZDZ-80 is without a doubt the best value for your money. Plenty of power and easy to operate.
RC Showcase is also a top notch operation that stands behind what they sell. I wouldn't hesitate to purchase another ZDZ from them.

I hope I get some of this great service others have mentioned. I'm really looking forward to trying to compete in IMAC with ZDZ powered airplanes. I have invested in two 80 singles and a 160 twin. Neither of my 80 singles for my practice/out of season airplanes make near the power they are claimed to so I sent one of them to Showcase for evaluation. It's been there for 8 days so far. I've called twice to date to follow up on it but near as I can tell it has not been run yet. They said they are real busy. I hope that means they are selling engines, not fixing them. Anyway, I'm not complaining, only stating what I know...so far.

My ZDZ was a real dog when I first got it. It says that the timing is factory adjusted and should need no further adjustment.

Mine was way off. Once I adjusted the timing, wa-la, easy hand starts and I'm getting around 6200 rpm with a Mejlik 3- bladed 24-10......

Say Marty:
What kind of prop/rpm are you getting out of the ZDZ-80?
How much time on the motor?
What exhaust system?
What fuel/oil.
Where is your ignition sensor positioned? Typically the sensor should be as far counter clockwise (most advanced position) as possible.
How much does your plane weigh? You should have unlimited vertical if the plane weighs less than 25 lbs. With a K&S can, it should good up to 29 lbs.

In response to your questions:

prop is menz 26-10 standard at 5700rpm when the stars are aligned. I can get just under 6100rpm with a Mejzlik 26-10 standard. I have 2 1/2 gallons through the engine. The fuel is 93 octane with 40:1 Penzoil 2 stroke oil supplied by RC Showcase. Ignition is not all the way to the end of the slot but biased towards advanced. Moving it all the way over has not improved anything so I put it back to factory spec. Airplane is 27# which would have nothing to do with the static rpm!

Here are the instructions for adjusting the hall sensor.

http://www.zdz-modelmotor.cz/zdz/en/dfu.asp?id=2

Roger I guess I"m missing your point. I know how to adjust the sensor and I know where to put it. In the case of the 80 single it's 6mm. I mentioned in my previous post that I put the timing back to factory specs. I only moved away from the factory spec because the engine is not doing well compared to what other's have/are claiming. I'm only seeing about 5600rpm on 2 different ZDZ80 singles with a Menz 26-10 standard prop. I even borrowed and tried a different Menz 26-10 standard to make sure mine wasn't mismarked or otherwise screwed up. The other prop was the same. I am currently flying one of these engines at just over 6000rpm with a Mejzlik 26-10 regular blade while Showcase checks out the other one.

I only gave you the URL, because someone said to set it to the end.

RC showcase should find out what the problem is.

Hello again Marty:
That you received 2 dud engines seems like an unusual bit of bad luck. What muffler are you using? If it's unusually restrictive, that could explain the lack of power. For reference, I have a ZDZ-80 single with 10 gallons of fuel through it. After 2 gallons of fuel it turned a Mejzlik 26x10 at 6700 rpm before a flight and 6500 rpm after a flight. This is using the J&A pitts muffler. I've seen at least a half dozen other 80 singles turn the same prop within a couple hundred rpm.

Are you using a Bisson muffler? I have heard they knock the rpm down quite a bit.

Is your throttle plate opening fully and not over-rotating or under-rotating?

Or....is your throttle rotating and opening in the right direction?

I know that once the throttle arm is cut off the shaft and another arm used in it's place, it's possible to rotate the throttle from idle to full in the wrong direction.....

I'm not sure anymore which direction is the correct way/ someone else can probably fill in this info.

Hi Guys,

Thanks for trying but the throttle arm was never cut off so it's not rotating the wrong direction and it is opeing fully. As for muffler, these numbers get better by 100rpm with a bare, open exhaust port so the muffler is not the problem either. They have great compression, even better throttle response but they just don't turn the rpm's guys are quoting.

Marty please send one or both of the engines back to us so we can examine/determine the problem(s).

We hate to see folks suffer when then don't have to, and you have suffered with this problem long enough. Mike Dooley tells me that you have been working with him on the phone, but it is time now to return the engine(s). We will either fix it or replace it. In either case we will test first, prior to shipping, to see that it meets our expectations, so that will get an engine that meets yours!


David Garrison
RC Showcase
ZDZ and RCS gas engines
http://www.rcshowcase.com

Marty,
With the bambula 26x10 I've been getting right around 6K RPM's, this is normal for this prop since it moves alot of air. I wouldn't be that concerned with the RPM's from the engine. I usually run mine a little rich, have about a gallon through it now. I posted a thread on this subject because I was also concerned that I was not getting the 6700+ rpm that other were getting.
Here is the link http://www.rcuniverse.com/showthread...545&forumid=37]

Hi David,

I did send you one. You've had it for 9 days so far.

Opps!

It will be attended to today!

Davud

I like my ZDZ80 so much I bought a second one to put in my new Ziroli Mustang.....

I currently have one in a Ziroli P40 w/mejlik 24-10 3-bladed prop and it really hauls *****!!!

Ok guys please clear some things up for me....
I just bought a H9 Cap with a ZDZ 80 single on it. It has about 1.5 gallons in it as of right now. Previous owner says the motor has been totally hassle free. Its picking up RPM every flight using a Menz-S 26x10.
I pick the plane up this weekend so I havnt seen the motor in person yet.

My questions are this,

Is there a upgrade available to a Wallbro Carb due to poor performance with the Bing Carbs? ( I think thats what the original Carbs are called ) I dont know which carb this motor has on it but as I said before it has been totally hassle free.

Is there a ignition unit problem. Older units Vs. a newer unit? How do I know if I have the older ign. or the newer one.

I saw a few posts back about adjusting the timing pick-up. Do you have to do this on all the ZDZ 80's. Doesnt the electronic ign. take care of this??


Thanks for any info.