no fire on a BS engine

[Anonymous-0]

I'm working on a 9HP Briggs. It is Model # 243431 Type 013 01 Serial #67H071. The history behind my problems are. It would always start until this fall when I tried it I had no spark. What I have done : 1/ put in new points and condenser. 2/ Put in new coil 3/ flywheel magnets are good. 4/ all wires are good 5/ Flywheel key is good. 6/ Gap between flywheel and coil is .010" and points are at .020" Still no fire to points or plug. WHAT THE HECK AM I OVERLOOKING?

 

[oldironman]

If you have an ignition key it may be shorted inside. I have also had new points and condenser that were bad. My bet is that it is the key.

 

[joe csuti]

Disconnect kill lead from eng that goes to ign sw,crank eng,check for spark,IF you have spark now then problem in tractor wiring or ign sw,IF still no spark with lead disconneced at eng,if eng has ext stop wire connection on flywheel cover or on bracket,disconnect wire from same that goes to points/coil,check for spark again,IF you have spark now then insulator/insulator washers on stop screw bad & point/coil lead shorting to ground,still no spark with lead disconnected then problem with points/condenser or coil itself,if when working on tractor you put +12v into lead going to ign on eng,you burned out coil,if you suspect/know this happened remove coil & take to local mower shop & have them check in a coil tester.

You said you replaced coil,quick question-when coil replaced,did you replace with a coil designed for point type ign or a magnetron(solid state)coil for pointless ign? A magnetron solid state coil will not work with points/condenser system.

 

[joe csuti]

Quick followup,if when checking for spark you have cover for points installed,remove cover & check for spark,if terminal for condenser not installed on point screw as shown in briggs manual it will short to cover when same installed on eng,grounding ign system(been there,done it)

 

[Anonymous-0]

Thanks guys for your comeback. I'm really stummped with this engine. Right now I have the engine out of the tractor. This is in an old Simplicity Landlord. So the switch is not even hooked to the engine now. I've tried every thing and I'm overlooking something. Thanks for your help.

 

[Anonymous-0]

Did you clean the points after installing and setting them?

New points are often oxidized, or get dirty from a feeler gauge, or handling. ....While this may sound ridiculous, it is quite common.

Some folks use a dollar bill or business card to burnish the contact surfaces. ....A piece of brown paper bag works well, too.

 

[e. r.]

Is the ground/kill wire from the points attached to a stud near the throttle lever assembly? If so, disconnect the wire and then turn it over and check for spark. THere is an insulating spacer on this stud and if installed wrong will ground it out and will not get spark.

 

[BrianJasper co. Ia]

You figure this out, I'll love to see what was wrong. I have the same engine/machine giving the same problems. I have a new Magnatron coil, maybe an hour on fresh overhaul. Sometimes it starts easily, sometimes won't hit at all no matter what. When it does run it misfires. If I find it, I'll post what I took.

 

[e. r.]

If you have a Champion spark plug in it, I would start by putting in an Autolite 456. Have had nothing but trouble the last 25 years with Champions. Every so often I will try em just to see if they've improved but the last one I tried did nothing but misfire. That was a year ago and I doubt I will ever try another.