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Collection, Preservation and Display of Old Lawn Mowers

Starter motor on Briggs and Stratton 5HP (Atco B24 Yoyale)


I've just acquired an Atco B24 Royale electric version mower, I'm trying to test the starter motor by using a battery charger to energize the device whilst off the mower. it turns over ( cog spins), but doesn't seem to move along the spindle (i.e. engage with the flywheel), any ideas what might be wrong




hortimech Tue, 18/03/2014

It could be that the charger isn't pushing out power to turn the motor fast enough, it could also be that the gear is sticking on the scroll and needs to be replaced, this was fairly common, find the model, type and serial number of your engine (usually stamped into the airshroud) and you should then be able to buy a new gear.


Dave C Wed, 19/03/2014

I am purchasing a replacement solenoid so will try the motor with that fitted first and see if the power from this is sufficient to move it up the spindle, thanks for the feedback

wristpin Wed, 19/03/2014

I would agree that the battery charger has probably not got enough "umph" to throw the pinion up the bendix. You need a fully charged battery - about 13.5 volts after charging. Also check all the connections including the earth.

While on the subject of electric start  Royales I have come across the same charging issue with several machines over the years. Since the advent of electronic ignition the flywheel is not removed regularly for attention to ignition points and this allows a build up of grass and debris inside it. This eventually binds between the charging coils and the circular ferrite magnet that is glued into the inside circumference of the flywheel. If you are lucky it just loosens the magnet and you can re- glue it. Not so lucky and it smashes the magnet and chews up the charging coils.

Dave C Thu, 20/03/2014


just to let you know I got a replacement solenoid and the starter motor  now works, you were right about the power not being sufficient from the charger... Thanks

PS: Would you know where to find the model number/age of the B24 Royale Acto mower, I've got to buy a replacement clutch cable and it appears to be different for each version of B24, or so I'm told

wristpin Thu, 20/03/2014

I think that at that stage the model id was on a black and silver sticker on the chassis.

If that's gone missing  can you post an image of the handle bars so that we can see the clutch lever arrangement. That will give a clue as to what cable is needed. Earlier machines had a "standard" chrome lever, poll up and latch to stop. Then there was a bar running across the handle bar, pull up to move and finally but as far as I know, only on the Tecumseh engined machines, a pull up bar with a "cable grab" requiring two actions to engage drive.