MGL V6 Failure

[fastj22]

I've had a V6 on my Jab 3300 for over 396 hours. The only issue I've had with it is overheating on summer cross countries where it might heat soak during refueling and will shutdown until it cools off. And that is rarely. In my new B model, I'm integrating a vent fan behind the panel to help that.

I do have issues with other MGL avionics and the Jab that I attributed to electrical noise. For instance the fuel flow reading becomes erratic at higher RPMs.

[sport65]

Thanks fastj22. I know its not a heat issue for me though, it will do it on 50 degree days right after start up. Do you use the NGK D9EA spark plugs? I've been told by a aerovee owner he solved this issue with resistive spark plugs. We are just not given this option by Jabiru.
By your first flight I assume your Jabiru is the three wire alternator I have seen in wiring diagrams. Mine is the two wire newer (2015) alternator that is suppose to charge at lower RPM. Maybe its the new alternator that is the issue then that the v6 cant handle some sort of electric noise from it. Anyone have the newer alternator engine with the v6?

[tx_swordguy]

Hey Jeff,
I am your neighbor up in Gainesville based out of KGLE. Got a onex on the field as well and another at a private field over near SHerman. I fly a sonex A model with an early jab 3300. I have a V6 and had noise associated with the engine on my right "mag" system. I replaced the coil but did not fix my problem. It may be the distributor but have not looked into that.(no noise with engine not running) I bought some clarity aloft headsets (in the ear) that GREATLY reduced ambient noise and made the mag noise tolerable enough to not worry about any more. I find it odd that you say the radio appears to be working from visual references ie, lights, numbers etc are there, but it does not transmit or receive shortly after starting the engine. If I understand you correctly you have sent your radio back and it is working to specs. My thoughts are leaning toward the headset hook up or the PTT button wiring. perhaps a ground loop or something else that is occuring with engine powering the equipment. Perhaps the PTT or headset connections are picking up noise because they are not shielded from it. In other words the radio continues to work but the signal is not getting from it to you.
Mark

[tx_swordguy]

on a side note I have been using the irridium plugs to get rid of the noise and it did not work. The plugs work fine and have no trouble starting etc because they are wire electrode and uses less to spark. I don't think that will be your problem but stranger things have happened.
Mark

[sport65]

Hey Mark! I plan on flying into Gainesville when I start flying again, and Sherman is my furthest airport for phase one.
Yes MGL sent me another radio and it did the same thing. My radio will not work though, it is not just noise. Your the second person to have an earlier Jabiru that the v6 works in. Still wondering if its a newer engine(gen 3) that has the issue.

Are the irridium spark plugs resistor type? I was told that made the difference.

[fastj22]

Thanks fastj22. I know its not a heat issue for me though, it will do it on 50 degree days right after start up. Do you use the NGK D9EA spark plugs? I've been told by a aerovee owner he solved this issue with resistive spark plugs. We are just not given this option by Jabiru.
By your first flight I assume your Jabiru is the three wire alternator I have seen in wiring diagrams. Mine is the two wire newer (2015) alternator that is suppose to charge at lower RPM. Maybe its the new alternator that is the issue then that the v6 cant handle some sort of electric noise from it. Anyone have the newer alternator engine with the v6?

I’m running iridium NKG plugs. I have a gen one Jabiru, so it’s a two wire alternator (ac) to a Kubota regulator. It doesn’t charge until 1800 rpm.
Have you tried powering the radio isolated from the ship power?

[lpaaruule]

My Jabiru was built around 2012. It’s SN is 2509.

My MGL works well most of the time, though I have had issues. Every once in a while, usually after warm restart, I won’t have any sound. Cycling power on the radio doesn’t seem to fix it.

A few days ago this occurred, and I happened to have my kid with me. He could hear everything, both me talking and other planes, in his headphones. I’ve tried different headsets to rule them out.

One time I was able to get the sound working again by flicking my mic. The loud noise seemed to wake up the radio. I don’t see how it could have been electrical.

I know this doesn’t help you, but I can’t help but wonder about the quality of these radios.

Sorry the yellow wire suggestion didn’t help. I will say however that the trouble you are having is making me think about replacing mine. My EAA chapther has been getting radios such as the Garmin SL 30 from Europe for as low as $600 since they have some new frequency rule.

[sport65]

The regulator I tried happened to have been Kubota. I looked up the iridium plugs and they are resistive. Yes, I used a car Battery outside the airplane with only the radio hooked up to it and it worked fine with the engine running.

I have also tried three different headsets to no avail. No problem with the yellow wire, suggestions are greatly appreciated. Nice score on the Garmin radios, If I replace mine I would want a 2 1/4" replacement so as to not leave a hole in my dash.

[sport65]

So I guess nobody has had issues with the resistive type plugs then? Why do people use them instead of the ngk d9ea's Jabiru says to use? Noise issues?

[fastj22]

The regulator I tried happened to have been Kubota. I looked up the iridium plugs and they are resistive. Yes, I used a car Battery outside the airplane with only the radio hooked up to it and it worked fine with the engine running.

I have also tried three different headsets to no avail. No problem with the yellow wire, suggestions are greatly appreciated. Nice score on the Garmin radios, If I replace mine I would want a 2 1/4" replacement so as to not leave a hole in my dash.

I'm not an electrical engineer, but would an oscilloscope identify what is happening to your electrical bus when the engine is running? Maybe its spiking/dropping voltage and that's causing the V6 to flip out. Are there portable oscilloscopes available?