So I recently purchased an unflown Ziroli 100" dauntless with a Zenoah GT80 installed. The engine is brand new.

I got the engine running but it was poor performance. The BEST I could acheive was 4400rpm with a Solo 20x10 3 bladed prop which by EVERYTHING I have read is actually on the very low end of prop sizes.

Further to that, I had to open the high speed needle 3 turns to get it to run at all. A far cry from the 1 1/4 I read on RCU and in the instructions.

So, I found a fuel filter that was to small, removed that, pulled the carb and cleaned it (it was spotless anyway) gapped and cleaned the plugs (which were new), checked the air gap for the mag (set to .014" as per manual), etc. The engine would not even fire at this point. I pulled the plugs, grounded them and spun the engine over with an electric starter and there was spark although IMO it seemed weak. We couldn't get the engine to even sputter.

So I go through everything again, attempt again to start the engine, this time there is zero spark, not even a hint of one. We checked all wiring, even bypassed the kill switch thinking it was a faulty kill switch. Wanted to try reducing the air gap but the damn bolts that hold the magneto on are completely seized, heat wouldn't budge them. At .014" though apparently that is correct, I don't know.

Gas is new gas, good quality 2 stroke oil mixed 32:1. Now I have a Mejzlik 24x10 prop on there (which is the prop to use from what I have read on RCU)

I'm at a loss. Further to that, Horizon has put me out on this engine. I sent them an email as they always have ridiculous wait times on the phone, and after 2 weeks have not gotten a response. I tried calling and using their call back number which they did call back but the guy I spoke to clearly had zero idea about anything. I told him all the things I have done and checked and he proceeded to ask if I had tried everything I already said I had done. I then asked him if I just send the engine in will Horizon install an electronic ignition on the engine, of course I would pay for it. He darted around that same question 3 times never answering if they would install it. Only saying "You'll have to send it in" and "Labor rate is $40 per hour billed in 15 minute increments". I asked 3 times about installing an electronic ignition (after all, they sell the damn things) and never received an answer.

Now I have also read that the stock mufflers are fairly restrictive and the builder added extensions to the exhaust to exit in scale location BUT, the extensions are a large diameter that while I could see SOME restriction, would not be causing a nearly 3000rpm loss nor should I think in any way that there should be any effect on ignition from that.

I have checked to ensure that neither piston has slipped on the crank (it was suggested to me to check to ensure both pistons were at TDC and BDC at the same time), I have checked compression on both cylinders, the carb has been cleaned, all wiring is good, it just boggles my mind that outside of a complete ignition failure, BOTH coils or plugs would fail at the same time.

I'm at a loss and particularly bummed out about this as it is a new engine, unfortunately it is past warranty on time. I keep hearing how reliable and good the GT80 is, but as of now, I'm not impressed at all.

Any advice? I'm willing to buy an electronic ignition and put it on myself, but I want to make sure I'm not missing something simple but difficult to track down before I spend anymore money.

Thanks in advance.
Jeremy

I should note too that I had planned on running without the mufflers to eliminate the restriction to see where the RPM would be, but I can't run it when no spark.......

You might try calling Ralph Cunningham at RC Ignitions / 1783 Whitehall / Williams, AZ. 928-220-5721

Without doubt, he is the Zenoah expert! He keeps trying to retire but I believe he still services some engines. Call him and discuss your problem, you won't be disappointed. I'm not sure whether the phone # is current but if not, someone will probably chime in with a correction. He likes to be called the Grumpy Old Man but he is a treasure of engine knowledge! Treat him right and he will do the same for you.

If you want to replace the ignition system, Milton at RC Extreme Power sells the RCExl ignition kit for the GT-80 which is a bolt on replacement for the original mag system. Here is a link

http://www.rcextremepower.net/

Good luck!

Bypassed the kill sw? The kill sw grounds out the mag. If you bypassed it you grounded out the mag. What you want to do is remove the kill sw.
When it was running did you check the exhaust on both sides to see if both cylinders were fireing?

Good catch Dirtybird! Maybe a simple problem.

Hi Dirtybird,
By bypassed I mean took it out of the equation. I tried it with the ground wire open and grounded, no spark either way.
When it was running I did have exhaust out of both cylinders yes, but it seemed the right cylinder was running richer than the left, there was oil spatter out of the right but not the left.

Call Ralph at the number above. If he will take it, it will come back brand new and run like a scared rabbet.




carl

This guy is in Canada. Sending it to Ralph might be expensive crossing the border twice.
If you have no spark you probably have a bad coil. Check it with an ohmmeter. it should be a hundred ohms or less. If bad it will not measure anything. (open)
A replacement coil will be cheap if you can find one.
If you want to go CDI your best bet would be to get one direct from China:
http://www.ebay.com/sch/i.html?_nkw=...36&poi=&crdt=0

Dirtybird, I don't care about the shipping cost, right now I have a $3000 airplane that is sitting gathering dust because the engine won't run. I'd rather send it to somebody who knows what they are doing and after my phone call with Horizon I don't feel they are the best choice. I will call Ralph and see what he says. Would one bad coil cause no spark in BOTH sides? I find it unlikely that both coils or both plugs would die simultaniously.

I spoke to Ralph this morning. All he could really suggest to check again is the connections of the coils to the mag. Great guy to talk with. If that doesn't net me any results I will be sending it down to him. Thank you for the contact info.

How are you checking the spark? A mag needs to have the rotor turning over rapidly to generate a spark.remove both plugs and put them in the leads and strap them to the engine where you can watch them. Then spin the motor with a starter. And you cant be out in the sunshine to see anything

That is exactly how I checked for spark.

OK if you have no spark and the coil measures good then I would just convert to CDI. It probably will be the cheapest thing to do. But then I am a cheapskate.

If the engine has been setting around for quite a while you probably should replace the gaskets and diaphragm in the carb. Your local small engine shop usually has the kits. Also Zenoah magneto engines need to be very wet to start, I always put my thumb over the choke and prop the engine until my thumb is wet. Usually starts in three or four flips. Make sure the prop is lined up with the hub correctly, on a two blade prop the blades are across the notches in the prop driver. Zenoahs like RPM A good alternative to replacing the magneto with ignition is a C&H jumpstart. They work really well and make starting easy without doing away with the magneto.
Larry

Is fuel getting to the cylinders?

Yes, as I said, it ran once poorly. I cleaned the carb (which was spotless). Checked everything. There is no spark. Ignition is what is not working at this point. Fuel is irrelevant if no spark. I'm just going to pull it off the airplane and send it in. I'm done fussing with it. Hate that I got a lemon....

Not a lemon,just a bad ignition.You sending it some where in Canada or USA.

If you are going to send it in I would think these quys are the best bet:

http://www.bennettbuilt.com/shop/Eng..._GT80_CID.html

Strange; that mag ignition is almost bulletproof.

No, send it to Ralph. He's the best, especially with Zenoahs and will take great care of you.

AV8TOR

Not much can go wrong with a magnet passing a coil of wire.loose wire or connection or there is a break in the coil.
If he can talk Ralph into looking at it,he is the one I would send it to.

I've had coils go bad. I had one that went bad in a weird way. The engine would start just fine, but would not rev up. Found out it was the coil; the automatic advance circuitry or the advance part of the coil itself, in the coil was bad. Installed a new coil and it ran perfectly. An Echo tech told me he had seen that before.

AV8TOR

Remember that all modern mag ignitions are now breakerless (no points). This means that many times the mag source coil, either integral with the HV coil or separate in the case of Zenoah ignitions has an internal circuit that can fail. These coils are more of a module than just a coil of wire. So yes, they can and do fail. I've had lawn equipment work perfectly one day then be unable to start with no spark the next. Replace the coil and they were good to go again.

Put a Rcexl electronic ignition on it, like 80 bucks on eBay. I have three of these on my zenoah twins, you can't go wrong. I do understand now by going with EI you have the added cost of a on/off switch, kill switch and battery. Very easy to hand start with this set up

I had a Quadra coil go out. No sputtering. It just quit. They will do it. I got the model number and called the manufacturer. $19 from them.

Who is this Ralph your talking about. Does he have a website