Briggs 233431 ignition question.

kopeck

Member
I have an old Briggs and Stratton engine that attached to a 3000w gen set that I'm trying to get going.

The big issues is the lack of spark. This engine has the breaker points mounted on the side, the magneto above the flywheel and the magnet in the fly wheel.

I've replace the point and condenser, set the points at .020 and still no joy. I've check the wring as best I could. There's a stud above the flywheel that has three wires attached to it. One from the points, the wire from the magneto and a wire that was attached under one of the screws that holds the points cover on. The stud seems to be isolated, ie it's not grounded.

That last wire didn't quite make sense to me, wouldn't that ground out the system and prevent spark? Maybe it had a kill switch mounter there at one point? Anyway I disconnected it but still no joy. When I tested the circuit with that wire installed both sides of the point were grounded at all time, with it removed it was grounded only when closed. I did remove the wire but I still didn't get any spark.

The magneto isn't pretty at all, that's the only part left to replace. Think I should order one or is there anything else to check first?

Thanks,

K
 

Check the key between the flywheel and crank shaft it dosent have to be sheered completely off to be bad, just a little off and it wont fire, that must be perfect to work.
 
Check the magnets on the flywheel for magnetism using a flat blade screwdriver. Could be they're weak, should attract that screwdriver well. Hal
 
Before I replaced the mag, I would try one of the electronic gizzmos that replace mechanical breaker points.
 
Likely, what you are calling the "magneto", which, in Briggs terms is the "armature" is bad. Depending upon the model #, age/serial # of the engine it MAY be possible to replace the armature with an updated unit that is a direct replacement but is electronic and eliminates the points, for about the same $ as replacing it with the original style.
 
I'll double check the key.

I was told it ran when it was put away so I kind of doubt the key would have anything to do with it but you never know.

Yeah, the armature, some of the parts lookups call it a magneto. I just bit the bullet and ordered one, they're not to expensive and it really the only item I can see what would be left. The one that's on there is a rusty mess, the wires are brittle and the casing its off most of them.

I can put a new wire in from the points to the stud as well, eliminate all possibilities. I still don't get what that second wire is for, it looks like it's always been there. The end that was attached to the breaker cover had a new terminal on it. It must of had a kill switch hooked in some where right? It wouldn't make sense to ground the points out?

Oh and the magnet grabs and holds my 1/4" screwdriver no problem, I hear that's the usual test.

K
 
When ever I get a Briggs that has a questionable
coil and no spark, what I do is convert it to
battery ignition, that way one doesn't have to worry
about the coil that is quiet expensive.
If you want I can provide how easy it is to convert
to battery ignition.
 
Well I've got spark. I stopped at the parts store and picked up a new plug and they ordered me the armature/magneto.

Came home and tried the new plug and heard it snap. Closer inspection showed a pretty decent spark.

Now I wonder if the parts store will take the armature back.

K
 
(quoted from post at 19:50:39 02/20/13) You should not buy new parts until you have thoroughly tested the old ones. I have checked them with a 9 volt battery.

While that's true I've personally never had a plug that wouldn't do a darn thing for me.

Live and learn I suppose.

I suspect they might let me "take it back" since I haven't even picked it up yet.

K
 
Cleanliness is very important on the old Briggs points. Over the years at the mower shop there were several times where just pulling a clean piece of paper thru the closed points would fix a no spark condition. If it had been sitting for a while its likely the points could have oxidation on them.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top