Hi Guys,

As some of you may know I've been having problems with interference and my mono. I mentioned the "basic" coil of wire which acted as the connector for the spark plug. Suspecting this was involved in some way I took the coil of copper wire out and replaced it with a proper spark plug connector and believe it or not it worked!! The servos did not jitter any more and the rudder and throttle responded properly to commands from the controller.

But now a problem has occurred with the ignition system. The engine runs for maybe a minute (and roughly at that) and then cuts out. We did a spark test and no spark was being generated. A few minute later a spark was being generated but then stopped again. After fitting the proper spark plug connector I had to move the coil as the spark plug lead was not long enough with the new connector on it. The earth wire I fitted to it was loose and after tightening this again there was a spark once again and the engine ran but after a minute or so gave up again....once again spark test showed no spark.

We suspect the coil (grey cylinder) is quitting or is it something else in the ignition system giving up. Is there any way to test this and if it is gone where can I get quality parts to replace the broken ones.


The suspect.


The earth wire i installed.

All the best,

Brandon.

Hi Brandon are you testing for spark by laying the plug connected to lead to earth?if so it could be a faulty plug but if not then look on the homepage on this site under RESOURCES then TROUBLESHOOTING where it tells you a bit about testing the coils.Hope this helps mate.Darren

Dazzido,

We tested it by laying it against earth as you described and with a dedicated spark tester and both worked sporadically but neither method showed the plug was sparking consistently.

Regards
Brandon.

Clean and tight connections of BOTH coils to crankcase. added grounding jumpers from secondary coils brass tab to case a GREAT add on. ... TIGHT bullet connector too !!

As for servo jitters .. MAKE SURE spark plug fitted is a RESISTOR type !!

We tried the 6V bulb method as described in the troubleshooting section but the bulb didn't light (we didn't have a 6V so used a 5.4V and 12V). We checked it with a multimeter and the voltage reading for the low voltage coil was 5 to 8 volts which should be enough???

How do we go about testing the grey ignition coil as it says nothing about this coil in the troubleshooting section. Can we just connect the two coils together and use a multimeter to check the voltage between the spark plug connector end and ground? If not how do we do it?

All the best,

Brandon.

Brandon RESOURCES/ENGINES/G260pum/G231pum manual.you will need an ohm meter so look on section 5 where it gives you the readings what each coil should read when working.so you know which wires look in the remarks section which tells you.hope this helps you mate.Darren P.S what i usually do to check coils is use a 6volt battery not a 12volt or you may blow it.connect your -earth battery terminal to the coil earth then have your HT plug lead about 2-3mm from the same earth connection and touch your +positive battery terminal to the red lead on off on,each time you touch then disconnect it should spark m8.only do this on the grey coil though not the red one.For the engine to run then stop then when its been left to run again something is breaking down if it was a simple wire it would,nt have run at all in the first place.check through methodically & you will find the trouble,do check them 2 screws that hold the red source coil to the engine.regards Darren

Hi Brandon

Personally I would take a breather and before doing complicated tests, I would consider carefully the physical changes that you made to your ignition system. The fact that this problem has surfaced only after the changes suggests its route cause is contained within the changes. Probably a simple cause and probably staring you in the face.

It would be my guess that the fault lies somewhere within the connections either altered or disturbed during the process.

As Scott said double check that bullet connector. Make sure it is tight and free of corrosion, also check that the wires at both ends are securely connected with good contact.

Do please let us know what is found to be the cause in due course. I hope you sort this quickly and I hope that the problem is a very easy one to fix once diagnosed.

Cheers
Craig

Craig they are only complicated if you don,t know what your doing,been in the motor trade i do though and am trying to help.

Grey coils have been known to do this kind of behavior...work for a bit then give out, then work again as they cool back down. There is a good chance it is the culprit. I would just order a new one...it's also a good idea to always keep a spare on hand.

Sounds to me like you only just discovered this issue now cause you couldn't even run the boat before you fixed the interference problem...correct? The old connector on the spark lead kinda leads me to think the previous owner might have been chasing the same gremlins.

Change that coil altogether and get a new resistor plug and go have fun!

Hi Darren

I noted your comment and I do apologise if my previous suggestion appeared to dilute the genuine advice that you offered. That certainly wasn’t my intention but I realise it may have been perceived that way. Sorry for that.

For my part (not having the technical knowledge that you have on coils and testing them) I would double check the less technical things first just in case it revealed the problem.

I say that because on one occasion I had my engine intermittently cutting out after starting really easy. In this case it proved to be an intermittent loss of spark. In this case the suspect was the kill switch which had not been used for a while and not cleaned or lubricated with WD40 in ages. My multimeter demonstrated that the switch was far from either on and off. The contacts were not firmly separating on release of the button. And I suspect that on starting the engine the vibration was causing current to pass though the switch and kill the spark to the engine plug.

Of course in this instance simply disconnecting the kill switch confirmed the trouble in an instant.

If as has been suggested the Grey coil could in fact be the culprit I wonder if that also might have been the cause of the radio interference.

I do look forward to an update from Brandon especially when the problem is eventually diagnosed.

Cheers
Craig