B with no spark

1) Does it produce a good sharp snap/click each 180 of flywheel rotation????? If not, shes never gonna fire at crank speeds. If not, the trip dog assembly in the rear (where mag couples to governor gear) may be stuck or rusted in which case a cleaning and lube may fix the problem. Look for this potential problem first.

2) If she does snap but wont spark, is there any kill switch stud or wire or push button on the side of the mag????? ?? If so, any wire to it can NOT be shorted or it kills the spark. I have seen the studs themselves go bad or their insulators shortign them to ground which kills the spark. Also, inside the mag any wire to that stud can NOT be touchign ground. Its supposed to have an insulated non grounded wire hooked to the points.

3) If the plugs wont fire, will the end of the plug wire all by itslef spark if placed within 1/8 inch of the tractor and the mag snaps????? ?? If so but not the plugs, the plugs are bad. Be sure the wires are not broke or leaky and are wire core, not auto carbon suppressor wires.

4) Make sure the points are not gray oxide coated or burned or pitted and open to around 0.015 on high cams.

5) Be sure the condensor wire is not shorted or frayed.

6) If she snaps loud and the points are clean and gapped and theres no shorted kill wire or stud or condensor wire and she wont fire the plug wires assumignm they are not broke or leaky, the rest of the mag could still be okay but theres a cap or rotor problem. With the cap removed, atatch a wire or paper clip from teh mags metal side frame to within 1/8 of the coils side output button/terminal and when the mag snaps, a good blue spark should jump that gap. If so but not out the caps terminals via a wire to 1/8 of frame, look for a cap problem like oil or cracks or carbon paths and be sure the lil spring in the cap is making contact with the coils side button/terminal. If its not, no spark out the caps terminals.

Theres more but its late and Im going to bed lol. Post back any more questions and assumign its really a mag, regardless of brand, if she dont wind and spring and trip a good sharp snap shes never gonna fire at crank speeds, but could still start and run fine if pulled if all else is okay.

John T Nordhoff in Indiana

KrisA

If NOT, do the cap remove test I described above to see if the coil is at least firing between a 1/8 gap at its output button/terminal each time the mag snaps over to a wire or clip atatched to its metal case. Be sure that lil spring in the cap goes up against the coils output button/terminal. If she fires there but NOT out the cap, you may have a cap or rotor problem as described above.

If still no fire there when she snaps and the points are clean and gapped, and theres no shorts and the condensor is not shorted, you may have a bad coil or a bad condensor. You can continuity test the coil, but even if it tests good there, it may still be breakign down at high voltage. If the condensor is shorted preventign a spark, it will still spark with it removed, but very weak.

If the coil and condensor and points and the spring trip assembly and cap and rotor are ALLLLL okay but still no spark, it could be a very rusted rotor or other rusty magnetic iron components.

If she snaps okay, I always suspect the points first, then the condensor, then the cap or rotor, then the coil, then the lil contact spring, then rust or corrosion.

Post back the resuslts.

John T Nordhoff

Okay, the coil wires should be one a thin laquered color and its the ground. The other is often a larger lookign black insulated one and its the one that goes to the points.

When the points are closed, there indeed should be a low resistance connection from anything hooked to them and the grounded case, cuz thats exactly their job, to close the circuit between whats hooked to them and ground when they are closed.

The coils low voltage primary (points circuit)is very low resistance, cuz its less wire length and bigger wire. However, teh high voltage secondary is much higher as its several thousand turns of smaller wire.

NOTE as I posted earlier, even if the coil passes the low voltage continuity test, it can still be bad cuz it only breaks down at high voltage. THEREFORE, it can be bad even if she shows continuity.

So youre gettign there and glad we can help. Keep postign back and we will get her going.

John T Nordhoff in Indiana

~You will have continuity between the [open] points stud & the case [about 1 ohm of resistance with open points]... If the points are closed you will have lower resistance. Opening & closing the points should change the resistance reading slightly [you will have to be on the 1 or 10 ohm scale]. Try disconnecting the condenser & check it's wire for a short to ground [it shouldn't have any continuity to ground].

~While in there, measure the resistance of the secondary side [between the coil's center button & the case ground], it should be over 5K ohms but under 10K ohms. Coil type & temperature could change those reading slightly so don't throw the coil out if you are a little over or under on those readings.

~If the coil checks out ok do the mag rotor [rotating drag test] I mentioned above to see if the magnetic rotor has it's magnetism yet.

~If that mag has the shorting stud sticking through the case, disconnect the internal wire running from the points to that stud just to eliminate that as the problem [sometimes those isolation washers look good but still allow the stud to ground to the case].

~If that mag is rusty inside there is a good chance that's your problem if everything else checks out OK..... ....

Keep posting more info and we will get you going. If the points and condensor are good and the rust is cleaned and you have no shorts and you still get no spark, its still possible the coil is good even though it passes a low voltage continuity test, assumign the rotor has magnetism.

John T Nordhoff in Indiana

~Depending on how much & where the rust is it could be effecting the mag operation so clean the rust from all the rotor & field laminations. Make sure the coil center core is free of rust [a problem area].

~If you are SURE the points are clean & making a GOOD contact [the number one reason those mags don't work is dirty points] then you will have to work through all the known problem areas.

~Start by removing ALL the wires from the points & using your ohm meter to check for the points stud being NOT GROUNDED with the points open & grounded with the points closed

~Then, check the condenser wire for going to ground [it shouldn't].

~Then, remove both coil pigtails & make sure neither one goes to ground [they shouldn't when both are removed]

~Then measure the resistance between the 2 coil pig tails [need around 1 ohm plus or minus a little]

~Then measure the resistance between the coil's center contact & the coil's ground pig tail [need around 6K ohms plus or minus a little]

~Have you removed the mag cap & tested for spark directly at the coils center contact?, if not do that to eliminate the cap & spark rotor as the problem.

~Post back with your findings & I will give you more specific tests.....