Plummit
Well Known Member
So a couple of months ago I taxied out for a flight and the Right mag was a dead soldier on run-up. The Mags had approximately 370 hours since their 500 hour inspection and service. Back to the hangar and I dropped the ignition switch as that was the easiest way to check the P leads on my Bendix 1200 series mags.
I found several of the wire terminals on the switch were loose. Don't know how or why but they were very loose. I tightened them up, congratulated myself on my find, and did another mag check. Everything checked out perfect.
A week later I flew up to Big Bear (L35) for a bite to eat. Upon leaving, the right Mag was again dead. It was a Saturday so I bought a new switch from Spruce and installed it. Another Mag check and everything was OK.
The following week I flew to Hemet Ryan (KHMT) and upon leaving, the right Mag was again dead. I checked the P leads and figured out that the wires were reversed on the switch! I had put everything back the way it came off when I replaced the switch so I know it was that way since I purchased the plane.
To top it off, I have been starting the engine on the right Mag which doesn't have an impulse coupling! (Yes I occasionally got kick-back) I finally pulled the left mag and had it overhauled. It seems that when you have a "500 hour inspection" done they only replace the points but not the condenser. The overhaul fixed the problem, and my best guess is that the 10 year old condenser was going "open" with heat. Something to watch out for when you have the 500 hour inspection done.
-Marc
I found several of the wire terminals on the switch were loose. Don't know how or why but they were very loose. I tightened them up, congratulated myself on my find, and did another mag check. Everything checked out perfect.
A week later I flew up to Big Bear (L35) for a bite to eat. Upon leaving, the right Mag was again dead. It was a Saturday so I bought a new switch from Spruce and installed it. Another Mag check and everything was OK.
The following week I flew to Hemet Ryan (KHMT) and upon leaving, the right Mag was again dead. I checked the P leads and figured out that the wires were reversed on the switch! I had put everything back the way it came off when I replaced the switch so I know it was that way since I purchased the plane.
To top it off, I have been starting the engine on the right Mag which doesn't have an impulse coupling! (Yes I occasionally got kick-back) I finally pulled the left mag and had it overhauled. It seems that when you have a "500 hour inspection" done they only replace the points but not the condenser. The overhaul fixed the problem, and my best guess is that the 10 year old condenser was going "open" with heat. Something to watch out for when you have the 500 hour inspection done.
-Marc
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