Dream to fly Posted December 21, 2017 Report Share Posted December 21, 2017 Plane is in annual, amazing how a year goes by. I have noticed the last three starts that the switch is acting funny. I'd like some input as to what could be wrong before I start going nuts looking for gremlins. If I hold the key in the CRANK position the engine will continue to crank fine but will not pop off. As soon as I release the key to the RUN position if I catch a compression stroke the engine will light off. I was under the assumption that the show of sparks system is operating while cranking so it should be lighting off during the crank position. It reminds me of the old fords that the ignition bypass wire broke and will only start when the key is brought back to catch the run terminals. Is it an ignition switch issue or my new mags not adjusted correctly? Quote Link to comment Share on other sites More sharing options...
N6758N Posted December 21, 2017 Report Share Posted December 21, 2017 Sounds like you have an issue with your retard setup, one of ( I think its the left mag) should have a retard wire coming from the switch. One of the mags should be off/retarded when the key is turned to start in order to facilitate easier starting. When you release the key you go back to both mags firing. Quote Link to comment Share on other sites More sharing options...
Dream to fly Posted December 21, 2017 Author Report Share Posted December 21, 2017 Just now, N6758N said: Sounds like you have an issue with your retard setup, one of ( I think its the left mag) should have a retard wire coming from the switch. One of the mags should be off/retarded when the key is turned to start in order to facilitate easier starting. When you release the key you go back to both mags firing. Ok.... I'm guessing that it is getting grounded and both are off. Ok that gives me something to look for. Too many hands in the past have been in this thing and trying to figure it out from a wiring diagram from the manual is like reading a map from another planet. color codes and wire sizes don't match. Quote Link to comment Share on other sites More sharing options...
MIm20c Posted December 21, 2017 Report Share Posted December 21, 2017 Take the signal wire off the starter solenoid and see if you can hear the SOS running. Make sure the connections are tight on the ignition switch. How long since the mags were opened up? Quote Link to comment Share on other sites More sharing options...
Hank Posted December 21, 2017 Report Share Posted December 21, 2017 Should start on the left mag. When my left mag crapped out in flight, on the ground it would just turn over and over, qnd as soon as I released the key she was purring along nicely. Check the wires for continuity. Make sure the SOS is buzzing. Check your left magneto, too. Quote Link to comment Share on other sites More sharing options...
Dream to fly Posted December 21, 2017 Author Report Share Posted December 21, 2017 Take the signal wire off the starter solenoid and see if you can hear the SOS running. Make sure the connections are tight on the ignition switch. How long since the mags were opened up? Both mags were replaced four months ago. New not rebuiltSent from my E6810 using Tapatalk Quote Link to comment Share on other sites More sharing options...
N6758N Posted December 21, 2017 Report Share Posted December 21, 2017 Just now, Dream to fly said: Both mags were replaced four months ago. New not rebuilt Sent from my E6810 using Tapatalk It doesn't sound like a mag issue. I'd bet you have a broken wire somewhere... Quote Link to comment Share on other sites More sharing options...
Dream to fly Posted December 21, 2017 Author Report Share Posted December 21, 2017 When I get down to the airport I'll post my wiring nightmare. I suspect it to be a broken wire by what you guys are saying. . The A/P doing the annual is not a spark chaser. It might be time to rewire. I know of a couple of wiring sins that need to be fixed. Quote Link to comment Share on other sites More sharing options...
Guest Posted December 21, 2017 Report Share Posted December 21, 2017 With the “P” leads disconnected from the magneto, connect an Eastern Electronics E50 magneto synchronizer to the “P” leads. Turn on the synchronizer, now turn the ignition switch through all positions, the lights on the synchronizer should correspond switch positions proofing the “P”leads aren’t crossed. Reconnect the “P” leads to the correct magnetos, disconnect the starter solenoid wire, remove all spark plug wires from the plugs, remove the upper plugs, turn the engine to top dead centre on the compression stroke for cylinder #1. Have an assistant turn the master switch on and turn the magneto switch to the start position while you hold the plug wires from cylinder #1 1/2” from the head. If the SoS is working a stream of sparks should jump from the wire to the engine, rotating the engine 180 degrees should see cylinder #3 do the same and so on for cylinders 2&4. Clarence Quote Link to comment Share on other sites More sharing options...
Dream to fly Posted December 21, 2017 Author Report Share Posted December 21, 2017 With the “P” leads disconnected from the magneto, connect an Eastern Electronics E50 magneto synchronizer to the “P” leads. Turn on the synchronizer, now turn the ignition switch through all positions, the lights on the synchronizer should correspond switch positions proofing the “P”leads aren’t crossed. Reconnect the “P” leads to the correct magnetos, disconnect the starter solenoid wire, remove all spark plug wires from the plugs, remove the upper plugs, turn the engine to top dead centre on the compression stroke for cylinder #1. Have an assistant turn the master switch on and turn the magneto switch to the start position while you hold the plug wires from cylinder #1 1/2” from the head. If the SoS is working a stream of sparks should jump from the wire to the engine, rotating the engine 180 degrees should see cylinder #3 do the same and so on for cylinders 2&4. Clarence That's what I needed. Thank you thank you thank you..... Sent from my E6810 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Guest Posted December 21, 2017 Report Share Posted December 21, 2017 I should have added, hold the ignition wires gently with a pair of insulated pliers. Clarence Quote Link to comment Share on other sites More sharing options...
Dream to fly Posted December 22, 2017 Author Report Share Posted December 22, 2017 I should have added, hold the ignition wires gently with a pair of insulated pliers. Clarence Lol... I knew that but thanks. Sent from my E6810 using Tapatalk Quote Link to comment Share on other sites More sharing options...
cbarnes403 Posted December 22, 2017 Report Share Posted December 22, 2017 He would have only done that once.... Quote Link to comment Share on other sites More sharing options...
Dream to fly Posted December 22, 2017 Author Report Share Posted December 22, 2017 He would have only done that once.... It would be electrifyingSent from my E6810 using Tapatalk Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 22, 2017 Report Share Posted December 22, 2017 +1 on the switch... Worth taking a look in the logs for the age of the ignition switch... They go a good 50 years, then create a whole bunch of gremlins on their own... My C’s switch failed the day the new owner came to fly away with it... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
triple8s Posted December 22, 2017 Report Share Posted December 22, 2017 FYI, I am not a professional aviation tech but have been around them for years and have seen this with my own eyes. With the starter disconnected if the engine crankshaft is in just the right spot and the SOS gets energized the prop will sometimes move! What I mean is the engine will light off for a stroke or two if there is even a tiny bit of fuel in the cylinders. I haven't seen one start this way but I saw a Piper pop off and turn over a couple blades with NO starter being energized was only the shower of sparks. So, all I am saying is BE CAREFUL around the prop. 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted December 22, 2017 Report Share Posted December 22, 2017 Just now, triple8s said: FYI, I am not a professional aviation tech but have been around them for years and have seen this with my own eyes. With the starter disconnected if the engine crankshaft is in just the right spot and the SOS gets energized the prop will sometimes move! What I mean is the engine will light off for a stroke or two if there is even a tiny bit of fuel in the cylinders. I haven't seen one start this way but I saw a Piper pop off and turn over a couple blades with NO starter being energized was only the shower of sparks. So, all I am saying is BE CAREFUL around the prop. In my description above I said to remove the ignition wires and the upper plugs. I too have had one running in the shop, it was quite exciting. Clarence Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted December 22, 2017 Report Share Posted December 22, 2017 2 hours ago, M20Doc said: In my description above I said to remove the ignition wires and the upper plugs. I too have had one running in the shop, it was quite exciting. Clarence It is a great way to clean the dust bunnies out of all the nooks and crannies! 1 Quote Link to comment Share on other sites More sharing options...
Rodeo John Posted December 24, 2017 Report Share Posted December 24, 2017 Is there a way to check to see if it is the switch ? And if it can be fixed or do you need to get a new switch ? Had the same thing happen in the Bahamas after getting fuel on the way back to the states ! Bad felling when that far from home and plane won’t start ! Quote Link to comment Share on other sites More sharing options...
Guest Posted December 25, 2017 Report Share Posted December 25, 2017 3 hours ago, Rodeo John said: Is there a way to check to see if it is the switch ? And if it can be fixed or do you need to get a new switch ? Had the same thing happen in the Bahamas after getting fuel on the way back to the states ! Bad felling when that far from home and plane won’t start ! Email me and I will send you the manual for TCM Bendix ignition switches. Clarence Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 25, 2017 Report Share Posted December 25, 2017 Take Clarence up on his offer... Then Check the age of your switch... If it is 50 years old and has 5k+ hours it may be a good idea to swap it out just because they wear painfully slowly... If it decides to not ground the mags... that could be really problematic... really worn parts don't always fail as expected... PP thoughts only, not a mechanic. Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
Skates97 Posted December 25, 2017 Report Share Posted December 25, 2017 2 hours ago, carusoam said: Take Clarence up on his offer... Then Check the age of your switch... If it is 50 years old and has 5k+ hours it may be a good idea to swap it out just because they wear painfully slowly... If it decides to not ground the mags... that could be really problematic... really worn parts don't always fail as expected... PP thoughts only, not a mechanic. Best regards, -a- I swapped mine out yesterday as part of the annual. It was $542 for the switch, but I didn't have any squawks to take care of and my AP/IA let me do it under supervision and didn't charge anything extra. The previous switch was the one that was put in the plane when it was built in 1965 and 5,346 Airframe Hours ago. It passed the 76-07-12 AD check, but I thought I would just get ahead of a failure that would eventually come. When possible, it is always better to do things on your time/terms than to wait for life to dictate the time/terms for you. 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted December 25, 2017 Report Share Posted December 25, 2017 You can take those switches apart and clean and polish the contacts, give them a little lube and make them like brand new. The contacts are made out of thick metal you can polish out a lot of pitting without compromising the integrity of the switch. 2 Quote Link to comment Share on other sites More sharing options...
Captnmack Posted December 25, 2017 Report Share Posted December 25, 2017 OR....You can buy a new set up from Electro Air in Mi. and get rid of the switch. Quote Link to comment Share on other sites More sharing options...
Skates97 Posted December 25, 2017 Report Share Posted December 25, 2017 11 minutes ago, Captnmack said: OR....You can buy a new set up from Electro Air in Mi. and get rid of the switch. If the new switch lasts as long as the old switch my grandkids will be flying with it long after I'm gone. Quote Link to comment Share on other sites More sharing options...
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