Guitarmaster Posted December 12, 2018 Report Posted December 12, 2018 Thought I would pass this on... I have a new-to-me airplane with Continental O-470's on it and I am still finding all the "easter eggs." One of those eggs came in the form of a hot mag. I found the hot mag during an in-flight mag check; no drop on the left mag on the left engine. Broken p-lead... easy... and it was... except... I fixed the p-lead and reattached to the mag. Cool. Taxied out and did my run-up only to find the left mag dead. Clearly it was being grounded out, but how? I checked all connections. Disconnected the p-lead again and it ran fine. The switch (it's just a toggle) tested fine as did the p-lead. Stumped... Finally went to the mag shop on the field and low and behold they had a Slick sitting on the bench with an insulating washer on the connection. I found the problem! An insulating washer on each post of each mag and, volia! Everything works as it should. The confusing part was, there was no washer on either mag so it appeared to be normal from my perspective. Someone left the insulating washer off of both the mags, it just so happened the lug I reattached was touching the case and grounding it out. Basically, it was a situation where either or both mags could have grounded ON THEIR OWN and that would have resulted in total engine failure over a washer. Moral to the story, if you have Slick mags, check the p-lead post and make sure there is an insulating washer installed! I wish I had taken pictures, but I didn't 1
Marauder Posted December 12, 2018 Report Posted December 12, 2018 Thought I would pass this on... I have a new-to-me airplane with Continental O-470's on it and I am still finding all the "easter eggs." One of those eggs came in the form of a hot mag. I found the hot mag during an in-flight mag check; no drop on the left mag on the left engine. Broken p-lead... easy... and it was... except... I fixed the p-lead and reattached to the mag. Cool. Taxied out and did my run-up only to find the left mag dead. Clearly it was being grounded out, but how? I checked all connections. Disconnected the p-lead again and it ran fine. The switch (it's just a toggle) tested fine as did the p-lead. Stumped... Finally went to the mag shop on the field and low and behold they had a Slick sitting on the bench with an insulating washer on the connection. I found the problem! An insulating washer on each post of each mag and, volia! Everything works as it should. The confusing part was, there was no washer on either mag so it appeared to be normal from my perspective. Someone left the insulating washer off of both the mags, it just so happened the lug I reattached was touching the case and grounding it out. Basically, it was a situation where either or both mags could have grounded ON THEIR OWN and that would have resulted in total engine failure over a washer. Moral to the story, if you have Slick mags, check the p-lead post and make sure there is an insulating washer installed! I wish I had taken pictures, but I didn't Hey Easter Egg guy, that is what you get for buying a 310 Now you get to see these “opportunities” in pairs. Sent from my iPad using Tapatalk Pro 1
Guitarmaster Posted December 12, 2018 Author Report Posted December 12, 2018 Hey Easter Egg guy, that is what you get for buying a 310 Now you get to see these “opportunities” in pairs. Sent from my iPad using Tapatalk ProTrue, but had it failed, I would have had another one to keep me going... Sent from my Pixel 2 XL using Tapatalk 1
carusoam Posted December 13, 2018 Report Posted December 13, 2018 Reminder... keep looking until all the Easter eggs are found, on both sides of the house.... Thanks for sharing the Mag and P-lead details, Matt. Amazing how many details there are to know... Best regards, -a- 1
Guest Posted December 13, 2018 Report Posted December 13, 2018 Be cautious when torquing the P lead nut, over doing it can damage the capacitor. Clarence
Guitarmaster Posted December 13, 2018 Author Report Posted December 13, 2018 Be cautious when torquing the P lead nut, over doing it can damage the capacitor. Clarence Thanks Clarence.... I am fastidious about torque, especially on things like this.Sent from my Pixel 2 XL using Tapatalk
Sabremech Posted December 13, 2018 Report Posted December 13, 2018 31 minutes ago, Guitarmaster said: Thanks Clarence.... I am fastidious about torque, especially on things like this. Sent from my Pixel 2 XL using Tapatalk But watch out when he has a Dremel nearby! 1
Guitarmaster Posted December 13, 2018 Author Report Posted December 13, 2018 23 minutes ago, Sabremech said: But watch out when he has a Dremel nearby! Love my Dremel!
Recommended Posts