OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines B&G starting problem

Hi all. I've got a Scott Bonnar rideon with a B&G 875ex motor. I can't start it, hoping for some historical understanding of this problem. The battery is good: my meter gets reads at the ignition switch; at the fuse; at the big fuse (whatever that's called); and at the butt cutoff switch. Is there a common problem with these things? One of the other safety switches perhaps. Cheers Brett

First thing I would do is jump the starter motor to see its not a stuffed starter (making sure brake on, deck disengaged etc). Some of them have a safety on the deck plastic discharge chute which gets knocked. check if there are any wires going down to the deck

Hi Tyler.
I have no idea on this particular mower but my thoughts are that there should be a plug down on the side near the starter motor. If you disconnect this plug that should disconnect any safety switches (I think) and then as you say positive jumper lead onto the starter motor and if the motor is going to start then it should this way. Then you have to trace back through the switches to find which one is the problem. This is how I would approach the fault finding using the information we have.

I would think the techs here need the same info as the techs on other forums do. Things like actual model numbers help us to look up the equipment so we know where we stand equipment wise.

122S07-0004-H1 I look forward to your input AVB.

Thanks NormK. It has a plug near the starter motor, but that doesn't seem to be it (though not too sure). I have already jumped the starter and that's not the problem. To be honest, I'm not exactly sure how to short the various switches to test them. Each switch has 4 or 5 terminals - do I just insert a wire and try to cross terminals? Power-in power-out I can test, but these bigger switches have got me stuffed.

Hi Brettsy,
These Briggs and Stratton motors have magneto ignition so first thing you have to do is establish if you have spark once you have unplugged the plug down near the starter. With the plug disconnected you will need a jumper lead to jump onto the starter motor terminal, spin the motor and see if you have spark. If you have spark and you jump the starter again with the plug lead on the plug the motor should start unless there is other issues with the motor or the carby. Have you had this running previously or have you just picked this mower up? And another thing to remember if you do get it running with the plug disconnected you will have no kill switch so you will have to pull the plug lead off the spark plug

Thanks NormK. The mower has been running perfectly for at least two years. The problem is the starter is not turning - ie the power is not getting to the starter solenoid. There are, as I see it, about ten things it could be. I've ruled out the solenoid, relay, fuse, big fuse, and a few other things. I suspect it's one of the safety cutoff switches or the ignition switch. There's one each for the blade engagement, seat, and park brake. I don't know how to test them. Power-in power-out points are easy to test with a meter, but I'm not sure how to test the safety cutoff switches which often have four or five wires going in. Incidentally, they all affect the power independently and don't go into a common switch point. I really just need to know how to test these switches.

Ahhh! Just found demos on youtube!

Can't find the problem. Tested everything. Taking it to the shop.

So what you are saying is the starter motor is not spinning. As I said earlier jump start directly from the battery to the starter motor. If the ignition switch is in the on position the motor should fire. If the motor is not turning over then it has nothing to do with all the safety switches it is either a dead starter or something wrong with the battery or the leads. By jumping directly to the starter motor you are bypassing all the switches just remember that

And maybe the starter motor is spinning but the starter gear has stripped, it is very hard trying to work things out with limited info. It is test this and test that till you can pinpoint it