Super08

My Feedback: (2)

The ground down ones must be arcing from the contact inside the cap down to the plug. There is no way they can touch with the top ground off. That just shows how strong the Rcexl units are. It will run much better with the plugs not ground off. Running it with the ground off plugs will drastically shorten the life of the ignition unit due to the high resistance and having to arc inside the caps to work.

aviator2002

I have just tried with a new plug and all I got with choke off was a few pops then nothing again so tried with choke and nothing except flooded plug again. The carb is obviously drawing fuel and I set the needles to the original carb which I think are High 1.5 turns and low 1.75 turns low may be 2.25 actually will have to check again.

soarrich

My Feedback: (98)

[QUOTE=aviator2002;11985682]I still have fuel flowing from the trumpet when I try to start the engine and when I take out the plug it is full of fuel so is obviously getting flooded. Since fitting the new carb all I have managed to get is a short pop from the engine then nothing except the flooding of the plug. I have double checked my timing /QUOTE]

John
You have a carb problem. It sounds like your inlet needle isn't seating properly. I'd take the metering diaphragm cover off and check that the inlet needle isn't stuck or have some crap in the bottom between it and the seat.

aviator2002

Cheers for that soarrich, I have just tried it again with the low needle closed to 1.5 turns but still the same after a couple of pops that's it so will probably have to take the engine out again to check the needle etc, I thought with fitting a new carb I would have eliminated all these problems but obviously not?? It just seems strange that with the new carb fitted the engine is doing exactly as it was on the old carb which was the same model as the new one. All these problems arose after the last flying session which went with no problems at all, I was setting up a smoke system when things started to go wrong not that I think that caused it all as when I got my other model out with a ZDZ50rv which also flew well last time out I have similar problems in that the ignition died and the carb wouldn`t suck fuel to the carb which I suspect is the diaghram but not had time to check yet.
Strange or misfortune that 2 engines of the same make have similar problems at the same time.
John

BadAzzMaxx

As posted by Super8 the 6A or 6F plug will work as long as it matches your plug cap on the ignition.

I use the 6A because it has a washer that helps to seal it.

On the sensor bracket I make, If you look from the front of the engine the sensor has to be set clockwise in order to time it right.

Set up right the magnet should be 1/4 to 5/16 past the sensor when prop hub is on top dead center.

Had to edit post for sensor setting.

Milton

aviator2002

I have removed the carb and checked inside for any sort of damage but found none and being as it is a new carb I didn`t expect to find anything really, the needle seems to be set ok and is not stuck open and no dirt to be seen but I gave it a blow out just to be sure I also removed the backplate from the engine to check the rotary valve for anything untoward but that seems to be ok also. I have attached a couple of photo`s to show both carbs and rotary valve.

My next step is to mount the engine to my test stand and see if I can get it to run on that but will need to wait for the rain to stop before that happens? The carb at the bottom of the photo is the old one.
If my next attempt to get the engine running fails I am at a loss as to what to do next particularly as the engine was fine before all this happened and as both carbs were dripping fuel I thought the fault may actually have been within the engine but examination has not shown anything amiss so any further help in solving my non start engine will be most welcome.
John

Super08

My Feedback: (2)

Make sure when you reassemble the carb that you get the button on the back of that rubber diaphragm into the slot on the end of the metering fork or is will not let the needle seat right. That will cause fuel to drip out of the carb and the engine to run pig rich.

aviator2002

Many thanks for that info Super08 I have just given the engine a couple of runs on my test stand and included video of them on this post.
The first run took a bit of starting and once running it was obviously very rich but as I was running without any silencer fitted I wasn`t too concerned until I stopped the engine and checked around the carb and it was leaking so I removed the cover and checked the diaghram to make sure it was seated correctly in the fork and reassembled it. On the second run as you will see in the video the engine ran a lot leaner and no leaks so now I have to refit the engine into my model and give it another run with canister fitted and see how we go then. The engine is inverted in the model so I am hoping everything will be ok and will post again either way.
Sorry the video is sideways as I did it on my phone and should have held it horizontal instead of vertical, will sort on the next one.

John
Sorry but I am having trouble downloading the video from my Pc I saved them as MP4 on my desktop but can`t seem to attach them, any advise welcome?

aviator2002

Engine is now back in my model after running up everything is working as it should be now so now I have to wait for the weather to clear after a week of high winds and rain is forecast. Very relieved all is ok once again and looking forward to get my plane back in the air again.
Now I can have a look at my other model with the ZDZ 50RV until the weather changes. That engine has a faulty ignition and carb not sucking fuel so need to get it sorted while the weather is un flyable.
Thanks for all the help from everyone who replied to my thread.
John

Super08

My Feedback: (2)

For videos I upload them to YouTube and then post a link to the video.

aviator2002

Thanks for that Super08 I don`t have a youtube account so I will sign up for one.

PiccoLino

I have a question for those of you who are still available to get back to this subject.
I also went through all the issues you posted, until the era of DA, DLE, etc.. powerful, reliable and lightweight engines came to our hobby. So my ZDZ got retired until recently a friend handed me a Suka 89 inch (China Models) that would requires 700 gr of ballast in the nose if I installed a DLA 58 on it for instance. There is nothing that I hate more than adding weight to my planes so I decided to recuperate my ZDZ, well heavier that the current competitors. Now, the first thing I did was to replace the original Falcon ignition with a RCexl by the steps that we all know very well by now. However I found that the magnet stuffed into the propwash has got a reverse polarity in relationship to the RCexl sensor. In other words, the RCexl sensor picks up the signal only if placed upside-down.
What would you do at this point?

Thanks

Super08

My Feedback: (2)

You used to be able to buy the sensors in a kit that were not assembled. It would come with the sensor and two plastic holders ( a short and a long). You would pass the sensor over the magnet on your engine to find the correct polarity and then glue it into the short or long holder which ever your engine required.

Super08

My Feedback: (2)

Here is a link to a kit that you find the correct polarity and then glue it into the holder. The kits can be found at many places around the world. The holder is then glued into a band at the correct length to reach the magnet. This is the kit I used on my ZDZ80 twin further up in this thread. There is also a little wedge in the kit that goes into the holder around the wire coming out of the holder. I sealed it with a drop of CA.

https://www.ebay.ca/itm/172355919987

PiccoLino

Thanks a lot Super08, it definitely looks like the easiest way to do it. I had no idea that such kits were around; thanks for the link too.

kmeyers

Wow, that is a quick and great response from Super08. Good to see this forum staying useful.