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I'm about three hours into Phase 1 and my engine seems to be running great. My previous flight I determined my secondary ignition was slightly advanced and turned trigger cap 1 degree clockwise. The engine ran better on the ground. The next flight I was flying about 45 minutes. The engine was running well and I decided to check the result of my timing change. The secondary ignition was on. When I turned off the primary ignition, the engine quit. It came back to life quickly when I turned the primary back on. When I landed I checked again by turning the primary off, and the engine quit. I checked the simple things first. The fuse had not blown and the switch had not failed. Power was going into the coils. I don't think two coils or two triggers would have failed at the same time. Does anyone have a suggestion?

Pull the trigger cap and look to see if the magnet is still there. Mine came out about 10 hours into flight testing. They are only press fit in with a little dab of glue. Others on here said they had the same issue when I asked about it back then. Thankfully the aerovee has a reliable and pretty foolproof primary ignition system.

Keith
#554

I took the trigger cap off today and found that the magnet had fallen out of the cap. Unfortunately it also cause quite a bit of damage to the two triggers. If it is a one in a million event, I would be the lucky individual who would experience it. Looking on the bright side, the primary ignition saw me home and the repair will be relatively easy.

Thanks for sharing. Since this failure has been mentioned several times on the forum, I suspect it is closer to a 1/100 engines event or more. Curious if the failures tend to happen at relatively low hours so that if you've made it to 100+, it's unlikely to fall out. It would be good to know what to look for.

I have nothing but positive comments about Sonex. They are a wonderful company who cares about their customers and their products. It is one of the reasons I chose to build one of their planes and use the products they support. Every time I needed help, Tech Support responded immediately. When I needed parts or had questions everyone I spoke to was helpful and pleasant to speak with.

I sent a couple e-mails to Kerry (Tech Support) about this issue before and after I removed and inspected the trigger cap. He responded right away each time. Once I found the magnet was missing, he responded that they had a production period where sub par glue was used to secure the magnet. My engine was over 10 years old, so apparently it should not affect newer engines. He said they would send me new triggers and a cap. I couldn't expect anything better, and i am happy with their product and support.

Glad you found the issue and are able to get it fixed. If Sonex finally admits to knowing about a period where sub par glue was used you would think they would have reached out to those owners and sent them replacement parts.before they failed or at least issued a service bulletin. You aren’t the first to have that failure and probably won’t be the last unfortunately.

Had the same thing happen but it didn't take out my triggers.

I had this happen today during the ignition check. When I shut off the primary ignition, the engine would have stopped if I had not turned it back on quickly. Last time I flew the Onex, I checked both the primary and secondary ignitions during flight to check the timing, making sure the CHT's didn't rise when operating on only the secondary ignition. So I know it was working during the last flight a week ago.

I went back to the hangar and checked the fuse. It didn't look blown but I replaced it anyway and still the same result.

After reading the earlier posts on this thread, I have a question. I presume that each trigger has a magnet in it. If that is true, it seems unlikely that both magnets would fall out at the same time.

After rereading the posts again, I realized that some people are talking about the trigger cap. Is that the round piece between the triggers that rotates that you turn to change the timing? I don't see anything in the manual about what is inside it but it makes sense that the magnet would be inside it and as it rotates past the triggers, it causes a pulse of electricity.

So will some who has been through this explain it to me?

Thanks.

Well I read some more in the Aerovee manual and found the answer. It is as I stated in my last paragraph.

So first I am going to be sure there is 12 volts supplied to the terminals on the back of the coils, and if that is true, I will take off the trigger cap and see if the magnet is there.

Thanks for being patient with a newbie.

You don't have to remove the trigger cap to check the trigger magnet. You can turn the prop until the magnet can be seen in the space between the triggers. I lost the magnet out of the trigger on a trip, the magnet fell out of the trigger cap. If the magnet is still there make sure it hasn't lost its magnetism.