electrical problem on briggs

10 years ago

28B707
1120 E1
03080520

I have this Briggs Engine on a Murray Rider.

Here's what I've encountered so far. It's been sitting up for a while. Has a new battery. Would not turn over, although the solenoid does click when the key is turned. I jumped the solenoid and it turns over but would not start.

There is no spark at the plug unless I pull the kill / ground wire off the coil. It then has a strong visible spark. Plug the kill wire back to the coil and no spark at all.

I've traced the wires and on this model of Murray, everything is quite open and easy to get to. No visible bare wires. Have checked the safety switches and all read as they're supposed to. Am pretty sure the solenoid will need to be replaced but am more concerned right now about what is grounding and causing the "no spark."

Could a faulty solenoid be causing the no spark?? I'm thinking it's not because when I disconnect the kill wire, jump the solenoid, engine turns over and spark is present.......... This one's got me stumped.

Any feedback, advice, instruction would be most appreciated........ Thanks Much

Comments (8)

bill_kapaun
10 years ago
"Have checked the safety switches and all read as they're supposed to"

So how does the seat switch read?
shillnav
Original Author
10 years ago
It reads closed when the seat is down and open when the seat is up.
bill_kapaun
10 years ago
I would work backwards from where the kill wire connects to the coil.
Unplug it from the coil and check continuity with the seat in both positions.

The seat switch sounds opposite of what it should be.

Maybe if you post Model/serial #'s, one "might" be able to dig up a schematic.
shillnav
Original Author
10 years ago
Model number is Murray 309000x8b.......... Thanks for your help.
shillnav
Original Author
10 years ago
ser # 7507107942d072
bill_kapaun
10 years ago
The schematic shows the seat switch as normally close (unoccupied).

When you are checking the kill wire, are you doing it with the key OFF or ON?
IF OFF, the kill wire is grounded.

We had another Murray just recently in which the schematic didn't match the actual circuitry.
Does your mower have a carb fuel solenoid? The schematic I have shows none.

Here is a link that might be useful: Schematic page 46
shillnav
Original Author
10 years ago
No fuel solenoid.............. I'll look at the schematic. Thank you very much !!
PRO
Forum Adviser
8 years ago
last modified: 8 years ago
First you should contact with the adviser I think http://testingandtaggingsydney.com.au/ would be the better for you.