OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Scott Bonnar 590 Magneto

Hi all, I have a beaut old SB 590 I am trying to get running. It was running fine a year ago before some fool left it outside for a 12 months.
I have serviced it to an average degree (pulled down and cleaned carby, oiled air filter, drained and replaced oil and fuel, oiled clutch and belt etc, new spark plug), talked to my local repairer, but confused them as it's a ripper oldie...
It turns over but has no spark evident, I can't get the magneto tested as it can't be removed due to a wire leading into the engine behind the flywheel. The repair guys don't believe the magneto is attached as they are young and stupid...

Any ideas???

the magneto is attached to the points behind the flywheel, i believe you can test it with an ohmmeter for resistance, you would have to google the procedure.

You can just spin the flywheel by hand, while holding onto a spark plug (that works) earthed against the motor. its either the magneto, the points or the sparkplug.

Cheers Tezza, I'll check it out tomorrow. Is the flywheel tough to remove?

So they've never seen a pre-1982 Briggs before [assuming it has a Briggs & Stratton engine]? That was when Briggs changed over to electronic ignition...

It would help us to help you, if you can post the Model, Type and Code numbers for the engine, if it is a Briggs. These will be stamped into the main cowling, in that order. Location will be either on top side, just above the spark plug, or on the side nearest the carby.


The breaker points and condenser are quite well enclosed and protected from weather on these engines.

What I would do first up, is to disconnect the cutout wire from the cutout switch on the carby [it's held by a clip], and see if there is spark then, as tezza has suggested. Disregard this bit if your engine has the cutout switch that acts directly on the spark plug!

It would also be worth having a look through the 'Reel-Type Mowers' forum in the 'Restoring, Customising and Modifying' section of the forums for 590 info. These mowers have a couple of failure-prone drive parts, which are now apparently unavailable.