Order posts by: 

RE:MAGNETOS

Joe,

Just to let you know I had a "stubborn" magneto a day or two ago as I proceeded with my post winter start up of all the tractors.  So I took it off and as per your suggestion I put it on the bench and spun it with a drill.  Amazing to see the spark first come back and then get bigger in just 2-3 minutes.  Put it back on the tractor and away she went!!  This is obviously why stubborn ones will start after a few yards towing - the magneto gets spun over fast - my old uncle obviously knew what he was doing when he said "tow the bugger!!"

John

RE:MAGNETOS

Just thought I would put on record my two "essential tools" for dealing with magnetos and distributors.

First a points (contact breaker) file and second a spark tester.  The file is special equipment for the hard surface of points.  To use the spark detector just place it between a plug and lead from the magneto and distributor and you essentially see a very much magnified spark like a neon light.  Much easier than holding a lead away from the plug whilst you hand cronk or starter crank an engine round.  It really does tell you if you have a worthwhile spark.

I got both from NAPA agents in N America

John
Attachments
P6130103.JPG

RE:MAGNETOS

John:

I am glad you tried my method and it worked for you as planned. I have had good luck doing it this way over the years. It's great to learn new tricks like this that is what this website was set intended for,

 It is way more exciting to jump on here and learn something new for the hobby instead of comming on here and listening to someone complain about how expensive it is to be a member.

Joe

RE:MAGNETOS

It seems an appropriate time to bring this magneto thread back up the list as winter hopefully soon works it's way out and keeping our fingers crossed for some good spring and summer weather in 2013.

I am sure we will soon be eager to have some of our tractors filled with water and running again in the next few weeks so thought I would discuss my recent experience with a Bosch U4 magneto fitted to my restored 1937 Green Pacemaker, the magneto was fully rebuilt in about 1987 and since then I could gaurantee that tractor would start on the third pull up of the crank, two with choke out, choke in and the third she would be away, no matter how long it stood without being run it always started the same way, so easy and effortless and never touched the magneto until now.

At Christmas this year decided to give this tractor a run, put gas in the tank, filled it with water and expected on the third pull up it would be away, well after several cranks it fired once, which encouraged me to crank more, knowing there was something wrong I kept cranking and eventually it started up and run well, but it should of started much better, so left it running for about an hour.
The next morning I decided to start it again, expecting it to go after three pulls, it would not even fire or cough, so took the points off which were coated in a green film, so thought here is the problem, a good clean with the points file and back together thinking it would start, still not a cough, so out comes the plugs to check if there was a spark, not a glimpse of a flash, so pulled off the distributor cap and about to start removing the magneto to try Joe's revival method or send away for rebuild something said to me wipe the fibre distributor wheel with a clean cloth, I took my handkerchief out of my pocket rubbed around the wheel including the brass insert, looking at my handkerchief it was covered in black soot, carbon from the brushes I expect. I put the cap back on pulled the crank up twice and she ran like a swiss watch and back to it's usual self of starting on the third pull.

I just wondered if anyone else has experienced this with their magneto's? 

Malcolm.

RE:MAGNETOS

It's been some time since there has been any talk about Magnetos, I've had no troubles with magnetos lately as it is too cold here to do much of anything but I did have an "ignition" problem a couple days ago here.

A couple days ago I was sitting in the house way in the back room on my computer and heard a very loud "bang". I didn't think much of it as my brother and nephew went to a gun show the day before and I figured they bought a new gun they were trying out in the junkyard, but usually when they go shooting in the yard there is many shots one right after another. I sat here thinking that was a bit unusual but soon forgot all about it.

A while later I went out to the shed to get the snow blower out and soon as I walked in the door of the shed I smelled rotten eggs. I knew immediately I forgot to take the battery charger off my air compressor  battery and figured it was being over charged. When I looked at the battery it was blown to bits and I soon figured it out that the large "Bang" I heard earlier was my battery blowing up... Amazingly enough the battery was so dry there was no acid left to blow all over everything in sight..

Gary, this is one more reason to own tractors and things with Magnetos and Cranks..

Joe
Attachments
IMG_0124.jpgIMG_0127.jpg

RE:MAGNETOS

Good that you have restarted this thread Joe.  I had occasion to take a magneto from my 12-20 for resurrection to my magneto man the other week and we got talking.  He reassured me that the magneto was perfectly OK and suggested that I check the strength of the spring in the impulse unit.  He told me that these should whizz round at 250 rpm but many with tired springs drop back to 120 and this is not good enough so you start to doubt the magneto.  Anyway I'll fit it with a new spring and see where we get to - but I thought it was a very good clue to supposedly poor magneto performance.

Anyone have ideas on this?

John 

RE:MAGNETOS

Well this is just to let you know that I fitted a new spring to the magneto impulse unit on my MH 12-20 and guess what?  - it started on the third pull !!!   So  this info from my magneto man was a valuable piece of information and certainly something that I had not given thought to before.  Although I still have 2 NOS springs I obtained in Canada, as a precaution and to have in reserve I am having some more made by a professional spring making company that I have found over here.

John

RE:MAGNETOS

John,

If you are going to get some made you can put me down for about 10+ depending on the price maybe even more.. I think they are the same spring in the 20-30s but could be wrong. I know this is a big problem with most as they get rusty and weak over time. I think if you get more made the price will come down the more you make. Let me know if this is possible.

Thanks,

Joe

RE:MAGNETOS

John , 
If you are taking orders? I could use 10 also.Any idea of price?
Some mags. seem to turn harder and require and good spring. 
Thanks'
Dennis