Primary ignition

[sidsx]

I'm doing the initial runs on the engine and have run into a problem with the magnetron's not killing the engine when turned off. The electronic side works fine, when I turn it off I see about 30 RPM drop. I checked to make sure I had a good ground at the "P" leads when the switch was off and open when on. I also have the magnetron's grounded to the engine. I disconnected both wires from the "P" leads on the magnetrons and connected a wire from each to a common wire, I then started the engine turned off the switch and pulled the CB for the secondary ign.( Electronic ignition) RPM Dropped about 30. Then touched the wires running from the magnetron's "P" leads to the negative battery terminal and the engine continued to run. This should have killed the mags, and it did not so this certainly rules out any airframe wiring. Has anyone seen the magnetron's fail in this manner? If so, It would be odd to have two fail at the same time. Then again I just got the oil pressure issue fix, It turned out that the new sender from Spruce had the exact same problem as the original one. Replacing it with one from GRT fix it! so saying I may have two magnetron's with the same failure wouldn't be a stretch. I'm interested in hearing any thoughts on this.

Thanks,
Sid

[Bryan Cotton]

Sid,
There was a bunch of bad magnetrons that had the issue you describe, back in 2014. I had one bad magnetron. Here is one thread on the subject:
viewtopic.php?f=7&t=2468

I am sure there are others.

[sidsx]

Well that has to be it. This is a 2014 aircraft...
Thanks, Bryan

[Bryan Cotton]

There was a service bulletin for the issue, now rescinded. You can find it here:
http://www.aeroconversions.com/support/aerovee_sb.html

[Onex107]

I made a simple mistake with my Aerovee ignition. After putting a few hours on it I discovered that the mags were not off when the switch was off. I used the wrong switch. You need a double pole switch to get the mags grounded when in the OFF position. I was dealing with HOT mags and didn't realize it.

[sidsx]

I have a new Magnetron It's the Oregon 33-345.So I thought I would try it in the upper position, I disconnected the Aft spark plugs to remove the lower mag from the system. The question is when checking from the "P" lead connector to the body should I have continuity? The old ones do not and the new one does. The new one does not work it kills the engine as soon as I turn the electronic Ignition off. (Even with the wire disconnected from the "P" lead) I mean it kills the engine it doesn't run bad like two cylinders are dead. So this mag is bad. Are the Oregon mags any good or do they just not work on this application? What magnetrons have people found that work? I cant see paying $81 each from Sonex.

Thanks,
Sid

[Bryan Cotton]

I've got the Oregon mags installed but not sure I'm happy with them. On the primary only the engine only runs smooth when it's leaned out a bunch. My next time I'll probably get the $80 magnetrons from Sonex.

[sidsx]

I'm all for supporting Sonex and I think it's important that they do well! I've sent them thousands since starting this build. I just think nearly triple the cost is A bit much for something that can be bought for $35 and free shipping. They could have just mark them up 20% and I would happily pay that because I really do want them to make money. I had already ordered one yesterday from Amazon. I'll see if it works (Hopefully I just got a bad one last time) if not I guess I'll bite the bullet.

Sid