Author	[Modern View]
bigboreG 06-04-2012 20:44:27 216.51.248.99 Report to Moderator	I am trying to figure out a friends 520...it wont stay running unless you keep your foot on the starter pedal ALL the time. Just enough pressure to make a contact but not engage the starter to flywheel. When you let up, it backfires and dies right away. Before i knew it did this, we put in a new rotary switch. Wired it up the same way the old one came out. The lights work, the amp gauge shows a drop when switch is turned on, only thing is it WILL start with switch off. However, if it is running and you have foot on starter pedal, if you turn the switch to off, the tractor will die. I have messed with it a few times, he put a new starter in it 5 yrs ago. Everything looks good, no bare wires or signs of a short anywhere. His dad bought the tractor new and has since passed, id like to get it fixed up for him but just cant find the problem. Anyone have any ideas? [Reply]   [No Email]
bigboreG 06-06-2012 20:30:06 216.51.248.99 Report to Moderator	Re: 520 electrical problem in reply to bigboreG, 06-04-2012 20:44:27   Resistor did the trick! Thanks guys. Dealer had one in stock, guess we sell alot the parts guys said. Must be prone to problems. [Reply]  [No Email]
machinery-man 06-05-2012 09:09:17 98.93.82.37 Report to Moderator	Re: 520 electrical problem in reply to bigboreG, 06-04-2012 20:44:27   The run wire goes to one end of the resistor ballast....wire comes from ignition switch to this this end other end to the coil. """"""Then""""" you have a wire from the coil side of the resistor block(actually) is just a connection...other end goes down to the starter switch so when you hit the foot petal activate the starter you will get a straight 12 volt to the coil on inital start up. When starter released power then is going through the ballast. Pretty simple. Having said all that I'd junk the whole thing and go to electronic ignition for a better start up and run condition for the tractor. Good luck. [Reply]  [No Email]
34gpa 06-05-2012 06:42:43 75.117.111.218 Report to Moderator	Re: 520 electrical problem in reply to bigboreG, 06-04-2012 20:44:27   It has a bad switch.I have 2 or 3 that will do excactly that.Look and see if the gas guage is moving when you turn on the switch,if not,the switch isnt working,or if the amp meter is showing a small discharge.The starter switch on the starter of the early ones has a small terminal that you run a wire from to the terminal on the resister going to the coil.It is energized when you step on the starter,and even though its not right,its the way it was designed.The tractor will run with the starter pedal pushed. Release it and it dies. So far I can turn the switch back and forth and it will make contact and work, or open it up and clean it,or put in a new one,bout $25,which would be the best.Look at the wireing dia. and you will see the small wire coming of the switch and going to the resister,check it for power,versus when you only have switch on [Reply]  [No Email]
John T 06-05-2012 03:39:56 216.249.82.117 Report to Moderator	Open Ballast Resistor in reply to bigboreG, 06-04-2012 20:44:27   I agree with Larry and M Man.... If the ignition ballast resistor is bad/open or miswired, that will cause the condition you describe i.e. will run ONLY when starter switch is (at least partially) engaged. Its located between the ignition switches IGN output terminal and the coils input (NOT to distributor) terminal and should read in the vicinity of say 1.25 to under 2 ohms ID SAY ITS BURNED AND OPEN or else isnt wired correct in series between switch and coils input. ALSO NOTE with Ign switch OFF it shouldnt start and if it does theres a wiring problem in the safety circuit from MAG or GRND on the switch down to the coils output (to distributor) terminal. As M Man described even with a bad/open ballast (which dont allow normal ON voltage from switch to coil) she can run if the start switch is engaged cuz the start switch sends full unballasted voltage to the coils input while cranking to by pass the ballast for better cold weather starting... See M Mans wiring diagram http://img.photobucket.com/albums/v437/M-MAN/SM-2029/50-1-JPEG.jpg John T [Reply]  [No Email]
LarrySTN 06-04-2012 21:00:05 71.54.95.232 Report to Moderator	Re: 520 electrical problem in reply to bigboreG, 06-04-2012 20:44:27   sounds like a bad ignition resistor. [Reply]  [No Email]
M-MAN 06-04-2012 22:01:49 184.39.46.7 Report to Moderator	Re: 520 electrical problem in reply to LarrySTN, 06-04-2012 21:00:05   X 2. She's running when the starter switch is pulled because it bypasses there to give 12v to the coil when cranking. [Reply]  [No Email]