Outdoor Power Equipment and Small Engines - Briggs no-start.

I hate the ones that only happen some of the time.

1990's Briggs 6hp lawn mower.
Electronic ignition.

Used to be hard to start, now won't start at all. Checked for spark and no spark. Changed plug, no start. Pulled flywheel and checked coil gap, no spark. Replaced coil and stop wire with Taiwanese part, regapped coil using part of the part box as shim, no start.

Put old coil and spark plug back in, pulled the handle and it started right up. Let it run for 1 1/2 mins, let go of the quick stop to let it stop. Sat for a minute, pulled the handle again, no start. Sheesh. Pulled about 20-25 times, no start.

I'm thinking maybe the stop switch is shorting? Maybe the coil isn't gapped correctly? Also, the new coil came with a stop switch connector with two wires, the original had only one. I taped off the second wire, but if there is a better place for it, I haven;t found any instructions.

Help is appreciated. (oh, I did check for gas)

jBoggs

The coil gap between the coil and the magnet should be between .006 - .010

I like setting mine to .008 I get a nice strong spark.

Another thing you should check are your points. Make sure they are moving up and down.

Electronic ignition...

Did I miss something?

I will re-gap tomorrow.

Thanks.

JBoggs

Find a clamp or something to hold the stop bail, follow the cable to where it hooks to the engine brake spring assy and by hand or with pliers, see if you can squeeze or help the cable pull the arm a bit more and check for spark. If you have spark now the cable needs replaced.

I pulled the stop switch housing off and the cable is fine. Mine has a little brass tang that the black wire from the coil connects to. It seems to always be in contact with the assembly as it is moved by the cable. The way the assembly looks, the tang on the brass connector should only connect when the shutoff handle is released thereby shorting out the connection and shutting the motor off.

I took continuity with a meter and it does not read an open circuit over the entire range of the cable. Shouldn't the circuit go open with with the handle pulled shut and when you release the cable, the circuit completes and the motor shorts? Or...do I have it wrong?

I am just guessing the if I bend the tang a little so it makes up in the slot only touching when the cable is released should do the trick but I don't want to monkey it up before I find out if I'm on the right track.

Thanks.

JBoggs

Did you try to pull the assy closed more with the bail held down???? Your cable is STRETCHED I am guessing as most do!! You can test it by unhooking that wire from the contact, if you get spark I am still betting it is due to your cable being stretched and no longer to complete full travel of the engine brake assy.

I believe you are right. I messed with the cable and assembly it does seem that although the cable looks fine it must have stretched. Thank goodness my wife saved the manual so I could get a number. I have ordered a relacement and should have it by Friday.

Thanks.

JBoggs

Glad you tested it further and hopefully will not spend any more time or money than necessary
Thx for the update :)

Got the cable, hooked it up, primed the carb, started on first pull. Runs strong.

Thanks A bunch.

JBoggs