Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Magneto failure CD-5

Matronics Email Lists Forum Index -> Yak-List

View previous topic :: View next topic

Author Message

glipaz

Joined: 11 Jan 2011
Posts: 107

Posted: Fri Jul 07, 2017 5:00 pm Post subject: Magneto failure CD-5

Conundrum:

At runup, Mag 2 failed (engine turned off).   Engine ran smoothly on Mag 1.  Returned to chocks and opened Mag 2 to discover a broken points spring.   Obvious hard break.   Replaced points and opened Mag 1 to inspect.   Discovered that the rotor on Mag 1 was completely loose (all three bolts were loose).  Tightened rotor on Mag 1, closed both mags and fired it up.   Started easily.   Mag 2 now worked fine but now Mag 1 failed.  What?!



Thought it might be a switch problem.  Tested Mag switch to make sure it was not a wiring short to ground and it checked ok.   Back to the Mag.



Inspected rotor and cap.  Ok.   Checked points.  Open fine.   Replaced cigarette.   Still wouldn't fire.   Replaced coil.   Still wouldn't fire.   Finally replaced Mag.   Motor fired and tested fine on both mags.   Runup Mag check normal.  



Note: we turned the bad Mag 1 by hand and could not get a spark out of the cigarette and the Mag turned fairly freely, without the normal flopping that the magnets provide.  



The mystery is this:  assuming Mag 1 was fine and Mag 2 had a hard break prior to shutdown (prior Mag checks on Mag 1 were fine) how did it fail after tightening down the rotor?   Why is it now producing no spark and seems to have lost its magnetism?   Prior to this both Mags worked fine on previous runups and flights.  



Gil Lipaz

- The Matronics Yak-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

Lancer

Joined: 21 Apr 2016
Posts: 30
Location: Cairns, Australia

Posted: Fri Jul 14, 2017 11:18 am Post subject: Re: Magneto failure CD-5

The rotor needs to be timed to the shaft which is why the 3 screws are in slots. Did you time the rotor??

- The Matronics Yak-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

_________________
You can run but you can't hide

dsavarese0812(at)bellsout
Guest

Posted: Fri Jul 14, 2017 1:56 pm Post subject: Magneto failure CD-5

"Time" the rotor?  How do you "time" the rotor?  Or do you mean the 

rotor needs to be properly ALIGNED?   The slots in the rotor screw holes 

are used to _position_ the finger (rotor turns counter clockwise and on 

2 finger rotors, it's the leading finger in the counter clockwise 

direction) of the rotor to point _directly_ at the scribe mark on the 

cover's mating surface next to the high voltage stick at the exact point 

where the points open, using a magneto timing box.



If anyone would like the diagram of the magneto under the cover, marked 

to point out the various parts used in setting the points and the fine 

timing adjustment, email me off-list and I will send it to you.

Dennis



A. Dennis Savarese

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 7/14/2017 3:18 PM, Lancer wrote:

 	  Quote: 	
		   



 The rotor needs to be timed to the shaft which is why the 3 screws are in slots. Did you time the rotor??



 --------

 You can run but you can't hide





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=470999#470999

- The Matronics Yak-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

Display posts from previous:

	Matronics Email Lists Forum Index -> Yak-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum