EA81 ignition modual failure

[WEST OZ FLYER]

Chook, what I am actually trying to work is why the ignition module died when I have a multi spark discharge unit now fitted. It has is own coil and brain box. Maybe I wasn"t clear a few posts back. The ignition module is only there to act as a switch to tell the box to do it"s job. I haven"t pulled the box apart but I would reckon that there would be a microprocessor to trigger the capacitor discharge.Previously this combination of coil and distributor had done 70hrs that I know of in my gyro on another engine, plus plenty of uncounted kms in a car. Also I would like to know why I have had such a short run with electrical components?

[chook]

Matt I"m sorry but I have no experience with the multi spark discharge unit. I have built the odd CDI unit in my younger years for non flying 4WD"s.Gyrocopters are awfully hard on electronics because of their vibration characteristics. Generally any electronics mounted around the engines have to be potted. This means encapsulated in resin. Also I really don"t know what the quality of the installation is like.Let me give you an example.Recently I was asked to have a look at a trike install as he was coming on one of our trips away. One of Adrians (Stoffels) "must haves" on these trips is a working VHF radio and the radio on this aircraft was US. On inspection I discovered that the battery was connected via push on spade terminals. One had so much corrosion and was so loose that it effectively disconnected. Because the power plant was a 2 stroke rotax, the battery acts as a voltage regulator and because it had become disconnected the rotax had put its full output voltage straight into the aircraft bus (well above 12 volts). He was extremely lucky that he only destroyed the radio and not his expensive navigation system as well.The lesson he learned was that all aviation battery installs require bolted lugs for their connection AND that it is wired so that the open circuit voltage is never allowed to be placed across the aircraft bus (fuse placement is critical).As I alluded to before - unless you really know what you are doing, experimenting with engine electrics in aviation is going to end in tears.Regards.......Chook.

[WEST OZ FLYER]

Chook, what really annoys me is not knowing what caused the problem. Therefore I can"t prevent it from happening again. If putting a ballast resistor between the distributor and coil saves the module I would look at that option for the future if I needed it. Doesn"t matter if it is a bandaid cure or the complete solution to the problem, it may save somebody"s life. The only conclusion I have come up with is that the new engine has 10.5:1 compression, big cam/valves and a lot more fuel putting more stress on the ignition than a standard EA81. After putting the MSD on and another module going I have no idea now. Points will do everything that I want reliably.KEVT, Chook and madmax thank you for your time, experience and knowledge.

[chook]

Matt not knowing is a real issue i agree.Many years ago I had a 1974 Kawasaki 900 motorcycle which had a charging regulator failure. This sealed unit was probably 60x80x20mm and Hartley motorcycles in Perth wanted $300 for a new one. Kawasaki had a peculiar method of charging that machine. The alternator was wound in a 3 phase configuration but what they did was bring each phase in as more current was required - so it was quite unique and thus expensive. Now as a tech there was no way that I was going to pay that price and in fact I was quite rude in telling them that.I took me a day to manufacture a thermal cutting tool and another 5 hours to cut the potting away but I finally exposed all of the components and the printed circuit board and managed to get a cct diagram of it.It had about 10 components in it and I rebuilt another one using brand new components for about $12. Their price was absolute theft.So if anyone out there needs the voltage regulator for a Kwakka 900...... The point I am making is if you have the time then anything is possible - I believe that you are in business and understand the current economics of fault finding. Sometimes and depending on your finances it is just quicker to go down the OEM path.Except of course if you are young with lots of time on your hands and you"ve got a point to prove after telling some nitwit to jam the new one up his a555!Regards......Chook.

[mad max]

Back in my younger days of copper ht leads and 6v cars and some of the newer 12v systems a guy started selling "turbo spark converters" which you scewed into the main coil lead. which increased the spark at the plugs. They had nice little fins and worked well. Some people made some good money for a while until someone chopped one up only to find a spark gap which simply forced the coil voltage up. Some mechanics even today can"t understand how resistor leads actually give you a better spark than wire leads.