WD ballist resistor 12 volt system

If you're switching to electronic ignition you may as well install a high performance 12 volt coil too. No ballast resistor needed then.

#2 is why I don't use them....
they should be designed and built better !
heck 40 years ago I was making my own and never ever had a problem....

Jay

The Pertronix units are great units in general. But, like anything else, you need to know what your doing. The E.I.'s are designed to use with the stock OEM coil, which means whatever electrical system your running, whether 6VPG, 12VPG, or 12VNG, you need to use the correct coil and hook-ups differ. If you go by the instructions that come in with the E.I.'s you won't have any problems as long as you can read and look at the pictures provided. You do need to remember when you want to charge up the Battery, NOT JUMP START  disconnect one of the Battery terminals from the Tractor while doing so, so you don't take the chance on throwing a spike to the E.I. module and blow the module out! This can be easily done by leaving the key ON when you went to start the Tractor and found the Battery was dead or low. Anytime you're running 12VPG or 12VNG with a 4 cylinder engine, you need to have 2.7-3.3 Ohms of resistance in the Ignition circuit. Using a 3.0 Ohm coil puts you right in the ballpark and a ballast resistor (which is a PIA anyway) can be eliminated so Mother Nature doesn't play havoc with it on hot humid or rainy days causing the engine to miss and run lousy.  The high performance coil that Pertronix offers is strickly optional. You don't have to purchase it with the E.I. kit as long as you use the correct coil for your application. If you want a little more fire in the hole, that's your option. Its all about being careful and watching what your doing. Most of the issues with E.I.'s are self inflicted because of forgetfulness or improper install. The units themselves are pretty damn reliable. The 6VPG one that I have in my B is going on 16 years old! We sell a ton of em' and we always have repeat customer's coming back and purchasing them for their other Tractors or when I'm rebuilding their Distributor have me install one. One of lifes nice little upgrades for the Tractor owner....
Steve@B&B

rob(ont) wrote: Steve, been having issues with a D17IV. 12 V neg ground. Ran good for 15 years, started missing this summer, by fall would not pull itself across the yard. Replaced the broken but still working ballast with a 3 ohm resistor, had 12.6 V in and out. Replaced coil (tried 2 different ones) with one labeled as "does not need external resistor". 12.6 V in and out across the primary terminals with no ballast. Full voltage at the points. Tried a combination of ballast and coil, same results. Would run well for 10-15 minutes, then back to missing badly. Tried two different point and condenser sets. Currently running but seem to be having issues with condensors based on weak, yellow spark. Any idea why I am not seeing voltage reduction at the points. Got everyone around here baffled. Any ideas?? Rob.

rob (Ont)
 you won`t see a voltage reduction
at the points when the points are open
it only  happen if the power is
being used ::    if you want to test it
u can used a ballast and a light hook
up to a battery and with your dvom
you can read what your voltage are

  clear as mud right 

ps did you change your rotor button
   
           B:-)      Dnoym

Rob,
Give me a call tomorrow or at your conveinence. I'll give you some idea's and I have a few questions to ask ya to get a little more backround on your delema.. Be happy to help ya out if I can...  Sorry, forgot to post the number!

Steve
(973) 632-5596


Edited by Steve in NJ - 29 Dec 2015 at 9:29pm

jaybmiller wrote: #2 is why I don't use them.... they should be designed and built better ! heck 40 years ago I was making my own and never ever had a problem.... Jay

What the difference, leave the key one with a points system and the coil will blow... All my gas tractors have 12 volt electronic ignition and the pertronix 3.0 ohm coil. Absolutely no problems and it always starts, rain or shine.

CArl , coil should never blow as it was designd to have 4 amps of current run through it and with the proper ballast resistor it will get 4 amps, Yup, be a tad warm but IF properley designed and installed correctly it should last for decades. probalm is nothing is designed and built properly these days.heck I've got a 67 mustang coil that fires up fine after 50 years.....

My real problem with 'electronic ignition' systems is they are NOT designed properly. They should not self destruct when boosting. If they do mfr left out a 25 cent component....same thing about 'wrong polarity' hookup, costs less than a buck to protect for that....

Jay

I understand completely. Its a shame how they beat up our Canadian comrades with all this border duty BS and what not. Everytime I send something up to Canada, I have to make the paperwork out down here and present it to the PO clerk to process before they do their thing. Its rediculous sometimes. If you still have troubles Rob, give me a call. Sure would like to help ya out if I can...
Steve@B&B

jaybmiller wrote: CArl , coil should never blow as it was designd to have 4 amps of current run through it and with the proper ballast resistor it will get 4 amps, Yup, be a tad warm but IF properley designed and installed correctly it should last for decades. probalm is nothing is designed and built properly these days.heck I've got a 67 mustang coil that fires up fine after 50 years..... My real problem with 'electronic ignition' systems is they are NOT designed properly. They should not self destruct when boosting. If they do mfr left out a 25 cent component....same thing about 'wrong polarity' hookup, costs less than a buck to protect for that.... Jay

Jay, the coil is designed to carry a certain amount of current, for a certain duty cycle... or as they used to call it... 'DWELL'. When the engine is running, the points are open for a large portion of the time, and closed for a small portion. Let's say that the engine is running 1000rpm... that's two cylinders firing every rotation, so 2000 times a minute, and let's be generous and say that the points are closed for 30 degrees of each firing event... that comes out to 60 out of every 360 degrees... or only 16.6% of the time.

If the coil's RESISTANCE amounts to only 4A of flow, the net power flow through the coil primary is only the equivalent of 0.66A. Since the coil is a REACTIVE element, it's frequency dependant, so as the engine speeds up, coil IMPEDANCE starts restricting current flow MORE, so the actual power equivalent will FALL.

This is why coils and points burn when the key is left on, but engine not running.

Now here's a not-so-big secret... coils that are built with intention of using external ballast, are made to operate at LOWER SUPPLY VOLTAGE than a 'normal' coil. A coil intended for ballast resistance is typically wound to fire substantially well at about 25% LOWER voltage... a 12v coil will fire well at around 9v... and they do this very intentionally, because when the engine is CRANKING, the battery is pushing the starter hard enough so that there may be substantially less than 12v available to fire the coil. SO... they wind the coil primary for 9v, and when cranking, it hits hard... but once you release the starter, the coil gets it's current through a ballast resistor, which limits current flow through the coil, so effectively, a 9v coil will survive at 12v. Unfortunately, it's another point of complexity and failure, but it works very well on high-compression V8's in extreme temperatures.

One could say that the 'ballast resistor bypass circuit' is the '70's era equivalent concept to the 'magneto impulser' of the brass era.

And the Trebuchet is the 'atomic bomb' of the 14th century...
And Audi is the Polaris of motorcars... and Polaris is the Cadillac of snowmobiles... Did I digress? Perhaps the end is near... oh yeah, that's right... it's tomorrow already...

HAPPY NEW YEAR, Everybody!