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

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

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

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.