This site is not affiliated with AGCO Inc., Duluth GA., Allis-Chalmers Co., Milwaukee, WI., or any surviving or related corporate entity. All trademarks remain the property of their respective owners. All information presented herein should be considered the result of an un-moderated public forum with no responsibility for its accuracy or usability assumed by the users and sponsors of this site or any corporate entity.
The Forum Parts and Services Unofficial Allis Store Tractor Shows Serial Numbers History
Forum Home Forum Home > Allis Chalmers > Farm Equipment
  New Posts New Posts
  FAQ FAQ  Forum Search   Events   Register Register  Login Login


Testing a magneto?
 Post Reply Post Reply
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
SC Dan K. View Drop Down
Silver Level
Silver Level


Joined: 08 Jul 2010
Location: Pendleton, SC
Points: 81 		Post Options Post Options   Thanks (0) Thanks(0)   Quote SC Dan K. Quote  Post ReplyReply Direct Link To This Post Topic: Testing a magneto?
    Posted: 31 Aug 2011 at 6:25pm
My 38 B had been sitting outside in several hard blowing rain storms. I went out to start it. After a little attention it started and ran for 20 second s. It cut off like the fuel was shut off. The fuel cutoff is open and I am getting plenty of fuel to the carburetor. I think there is no spark. I can't see anything wrong. What do I look for on a magneto? Thank you for any help.
Back to Top
Sponsored Links


Back to Top
Leon B MO View Drop Down
Orange Level
Orange Level


Joined: 12 Sep 2009
Location: Old Monroe, Mo
Points: 2178 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Leon B MO Quote  Post ReplyReply Direct Link To This Post Posted: 31 Aug 2011 at 7:21pm

To test for spark, I take out # 1 plug, put the plug wire back on the plug, ground the plug to the motor. I take the wires off the rest of the plugs to make sure it dont start, you can even take plugs out to crank it over easy. Hand crank until you feel compression on front plug hole, keep cranking slowly, the next click of the mag should give you fire at the grounded plug.If you have fire, put it back together. Before you install the plugs put a small squirt of fuel right in top of each piston. After putting the plugs back in, try starting it. If I let the U sit all winter that is the only way I can get it to start.

Good luck
Leon B MO
Uncle always said "Fill the back of the shovel and the front will take care of itself".
Back to Top
jccleav View Drop Down
Orange Level
Orange Level
Avatar

Joined: 11 May 2011
Location: Indianola IA
Points: 211 		Post Options Post Options   Thanks (0) Thanks(0)   Quote jccleav Quote  Post ReplyReply Direct Link To This Post Posted: 31 Aug 2011 at 9:44pm
Did it die after you took the choke off?  I guessing you do not have water in the gas since you said there is plenty of fuel to the carb.
Back to Top
Unit3 View Drop Down
Orange Level
Orange Level
Avatar

Joined: 17 Oct 2009
Location: NC Iowa
Points: 5571 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Unit3 Quote  Post ReplyReply Direct Link To This Post Posted: 31 Aug 2011 at 9:58pm
Years ago dad told me to hold onto the end of the wire on a small B & S engine as he slowly pulled the rope. I was young and didn't know. Somethings you never forget. FYI Not a good way to check for spark, but it worked. He knew right away the little engine had plenty.  
Back to Top
wkpoor View Drop Down
Orange Level
Orange Level


Joined: 25 Apr 2010
Location: Amanda, OH
Points: 825 		Post Options Post Options   Thanks (0) Thanks(0)   Quote wkpoor Quote  Post ReplyReply Direct Link To This Post Posted: 31 Aug 2011 at 11:36pm
Mags can get water in them and the only fix is to take off the covers and blow out or let dry. Couple of yrs ago I towed a farmall Cub to a show in pouring rain. After I got there it wouldn't start. Discovered wet cap. Dried it out and it started right up. Went to plow and it started acting up again. Pulled off cap and it was wet again. After 3rd time I went a little deeper and found the case and rotor full of water. It just kept evaporating up and condensing on the cap. So basically getter dried out and go from there.
Back to Top
Steve in NJ View Drop Down
Orange Level Access
Orange Level Access
Avatar

Joined: 12 Sep 2009
Location: Andover, NJ
Points: 11925 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Steve in NJ Quote  Post ReplyReply Direct Link To This Post Posted: 01 Sep 2011 at 7:40am
Moisture plays havoc with any Mag. A little spritz of Brakekleen on the points and some compressed air will dry the inside of the Mag out, if its a "no spark" situation from moisture. Make sure the gasket(s) on the cover is in good shape. If its old and not sealing well, moisture will get in there and oxidize the points everytime. Sometimes the condensor fails which will cause' a no spark situation also... HTH
Back to Top
SC Dan K. View Drop Down
Silver Level
Silver Level


Joined: 08 Jul 2010
Location: Pendleton, SC
Points: 81 		Post Options Post Options   Thanks (0) Thanks(0)   Quote SC Dan K. Quote  Post ReplyReply Direct Link To This Post Posted: 01 Sep 2011 at 8:00pm
Thanks everybody. Definitely no spark. Good friend farm all enthusiast stopped by and took a look. We sprayed everything including inside magneto with WD-40. That's always displaced any water if I had a wet ignition system. Still no spark. I'm going to call a magneto expert after the weekend tractor show. Don't guess this one will be at the show. If anybody is at dacusville,SC this weekend I hope to find one tractor that will run
Back to Top
SC Dan K. View Drop Down
Silver Level
Silver Level


Joined: 08 Jul 2010
Location: Pendleton, SC
Points: 81 		Post Options Post Options   Thanks (0) Thanks(0)   Quote SC Dan K. Quote  Post ReplyReply Direct Link To This Post Posted: 01 Sep 2011 at 8:04pm
No one will volunteer to hold a spark plug wire  :)
Back to Top
beeman View Drop Down
Orange Level
Orange Level
Avatar

Joined: 02 Jan 2011
Location: Alabama
Points: 230 		Post Options Post Options   Thanks (0) Thanks(0)   Quote beeman Quote  Post ReplyReply Direct Link To This Post Posted: 01 Sep 2011 at 8:05pm
Old Harley Davidson Sportsters [XLCH models ] had Fairbanks Morse magnetos up till 1969. They were prone to getting moisture in them  especially down in the humid South where I live. An old mechanic showed me how to cut little pieces  of a sanitary napkin and stuff them down into the case of the "mag' to absord the dampness.  Change them out with fresh  once in awhile... Worked great!!  [tough part was explaining why you kept one of those things in your toolbox .......]
1949 B   3930 Ford- Have owned other Orange ,green,red,yellow,dark green tractors and equipment.
Back to Top
wkpoor View Drop Down
Orange Level
Orange Level


Joined: 25 Apr 2010
Location: Amanda, OH
Points: 825 		Post Options Post Options   Thanks (0) Thanks(0)   Quote wkpoor Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep 2011 at 12:09am
Originally posted by SC Dan K. SC Dan K. wrote:

Thanks everybody. Definitely no spark. Good friend farm all enthusiast stopped by and took a look. We sprayed everything including inside magneto with WD-40. That's always displaced any water if I had a wet ignition system. Still no spark. I'm going to call a magneto expert after the weekend tractor show. Don't guess this one will be at the show. If anybody is at dacusville,SC this weekend I hope to find one tractor that will run

I like the brake clean but WD40 no way. Any residuals left over could create a secondary path to ground and thus no current to plug. I would do as Steve said and brake clean everything you sprayed with oil especially the cap. And look closely for cracks. High voltage will travel in air much easier than rubber or Bakelite. If that don't do it Ohm out the coil or if its an old gooey black one change it anyhow. Unless you've got dead magnets they aren't hard to bring back. Better yet send to Steve and problem solved.
Back to Top
Gerald J. View Drop Down
Orange Level
Orange Level


Joined: 12 Sep 2009
Location: Hamilton Co, IA
Points: 5636 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Gerald J. Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep 2011 at 1:25am
Actually Water Displacer number 40 was developed for this water removal task from aircraft magnetos. Its use as a pseudo penetration oil and temporary lubricant came later.

Gerald J.
Back to Top
wkpoor View Drop Down
Orange Level
Orange Level


Joined: 25 Apr 2010
Location: Amanda, OH
Points: 825 		Post Options Post Options   Thanks (0) Thanks(0)   Quote wkpoor Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep 2011 at 3:46pm
Never seen WD40 in aviation. Reason I'm told is to be used in Avaition it must have a mil spec and to do that they must devulge the formula. WD40 has no mil spec. I've been a tech for 26yrs.
Back to Top
CTuckerNWIL View Drop Down
Orange Level
Orange Level
Avatar

Joined: 11 Sep 2009
Location: NW Illinois
Points: 22824 		Post Options Post Options   Thanks (0) Thanks(0)   Quote CTuckerNWIL Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep 2011 at 3:53pm
Bil, go to this link and read the story. http://www.wd40.com/about-us/history/
http://www.ae-ta.com
Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

This page was generated in 0.156 seconds.


Help Support the
Unofficial Allis Forum