no spark,coil?briggs 17.5 h.p ohv

[dwint]

I started a thread awhile back.someone gave me a murry model 425001x8d with a briggs model 31c707,type 0154e1 17.5 h.p.i bought a battery and starter and it turns over great but no spark.mice chewed into the coil wire but not completely threw but still no spark.is there a way a shop could test this for me or should I buy a new coil.every safety switch was disconnected when he gave it to me and im hoping its the coil

 

[EngineMan]

One additional test you can perform. Check the impedance (resistance) of the secondary circuit at room temperature. Hook an ohmmeter test lead to the spark plug terminal of the high-tension lead and another to the lamination stack (ground). Your resistance reading should range between 2,500 and 5,000 ohms. If infinite (no continuity), an internal open circuit exists. Replace the coil. If infinite and the engine runs, your problem is an internal break of the high tension lead, a poor attachment of the spark plug terminal or improper mating of the high tension lead to the coil. A pin within the coil body skewers the lead. If the pin does not contact the wire core, there will be no continuity. The coil will often have enough available voltage to jump the gap, so you see spark. The internal arcing that occurs within the high-tension lead will eventually create enough resistance that ignition system performance will suffer. If your resistance reading is much lower than 2,500 ohms, an internal short exists. Replace the coil.

MOST IMPORTANT: Be sure to isolate the coil from the equipment wiring harness as well as the engine's wiring harness. That's right, unhook the ignition grounding lead from the coil itself and use the spark tester. Many a technician is fooled into replacing a good coil because the coil grounding lead was shorting out against a piece of sheet metal. DO NOT attach the tester to the spark plug for this test. The engine may start. Without the grounding lead installed, you won't be able to turn it off. If the coil is properly grounded to the engine block, engine speed is at least 250 RPM and the flywheel magnets are OK, there should be spark present in the window of the tester. If not, repeat the test double checking your procedure. Still no spark? Then and only then, replace the coil.

 

[Kodie's Lawn Service]

I started a thread awhile back.someone gave me a murry model 425001x8d with a briggs model 31c707,type 0154e1 17.5 h.p.i bought a battery and starter and it turns over great but no spark.mice chewed into the coil wire but not completely threw but still no spark.is there a way a shop could test this for me or should I buy a new coil.every safety switch was disconnected when he gave it to me and im hoping its the coil

even if the coil where good it would be best to replace it due to the fact that the spark may go across the metal if it where to touch all so it could be a bad connection on the mower

 

[Carscw]

Rap the wire with some rubber hose

 

[dwint]

I don't have a ohm meter but maybe I can have someone test it for me.i am using a push button starter and will be using a toggle to kill the engine.right now I just put the coil on and did the air gap with a card.i also cleaned the magnets and they are strong.i only need the ground wire from the coil to kill the engine correct?one from toggle to frame and one from toggle to coil?

 

[Kodie's Lawn Service]

I don't have a ohm meter but maybe I can have someone test it for me.i am using a push button starter and will be using a toggle to kill the engine.right now I just put the coil on and did the air gap with a card.i also cleaned the magnets and they are strong.i only need the ground wire from the coil to kill the engine correct?one from toggle to frame and one from toggle to coil?

yes :thumbsup:

 

[PVHIII]

One additional test you can perform. Check the impedance (resistance) of the secondary circuit at room temperature. Hook an ohmmeter test lead to the spark plug terminal of the high-tension lead and another to the lamination stack (ground). Your resistance reading should range between 2,500 and 5,000 ohms. If infinite (no continuity), an iinternal open circuit exists. Replace the coil. If infinite and the engine runs, your problem is an internal break of the high tension lead, a poor attachment of the spark plug terminal or improper mating of the high tension lead to the coil. A pin within the coil body skewers the lead. If the pin does not contact the wire core, there will be no continuity. The coil will often have enough available voltage to jump the gap, so you see spark. The internal arcing that occurs within the high-tension lead will eventually create enough resistance that ignition system performance will suffer. If your resistance reading is much lower than 2,500 ohms, an internal short exists. Replace the coil.

MOST IMPORTANT: Be sure to isolate the coil from the equipment wiring harness as well as the engine's wiring harness. That's right, unhook the ignition grounding lead from the coil itself and use the spark tester. Many a technician is fooled into replacing a good coil because the coil grounding lead was shorting out against a piece of sheet metal. DO NOT attach the tester to the spark plug for this test. The engine may start. Without the grounding lead installed, you won't be able to turn it off. If the coil is properly grounded to the engine block, engine speed is at least 250 RPM and the flywheel magnets are OK, there should be spark present in the window of the tester. If not, repeat the test double checking your procedure. Still no spark? Then and only then, replace the coil.

Very cool avatar

 

[reynoldston]

I don't have a ohm meter but maybe I can have someone test it for me.i am using a push button starter and will be using a toggle to kill the engine.right now I just put the coil on and did the air gap with a card.i also cleaned the magnets and they are strong.i only need the ground wire from the coil to kill the engine correct?one from toggle to frame and one from toggle to coil?

Go to Harbor Freight or E-bay and you can buy a cheap multimeter for less then 5 dollars. It has a ohm meter on them and also it is handy all kinds of electrical test around the house or your work shop.