Motor help, please

[wristpin]

The Brook motor on my lawnmower bottom blade grinder has developed a starting issue - seems to have coincided with the colder weather! It gives all the indications ( to my untutored mind!) of a capacitor or centrifugal switch issue but there is no obvious external capacitor so presumably it may be one of those "cube" ones fitted internally? When it was running correctly one could hear the centrifugal switch click as it slowed down.
All advice welcome - thanks

 

[penfold]

Motors with centrifugal switches and start windings do not have capacitors; if the switch has gummed up or gone high resistance through corroded contacts or the switch failed in the 'run' position then it most likely will not start and will sit there humming at you until the winding burns out; in the short term you can get around the failure by spinning the motor by hand to get it going.

 

[wristpin]

Thanks, will go looking for the switch and see what’s to be seen.

 

[Bladevane]

I had a pretty old Gryphon motor on my pillar drill. The centrifugal switch failed and I was unable to repair it or get spares. Ended up going for a new motor.

 

[brightspark]

might just be stuck on open on the shaft .give it a clout with a hammer if it runs just take end cap off and give it a squirt with wd40 my drill used to do it . eventually I lubricated it

 

[penfold]

That happened with a MetroVick motor I had; the slider that moved along the motor shaft had stuck in the 'start' position with rust, it started ok but the 'start' winding is not designed to be energised for more than a few seconds and quickly became hot, risking burn out if left on. After dismantling, fettling the rust off the visible shaft with wire brush and 3M green pan scourer, oiling and coaxing the thing with light application of a mallet, normal service was resumed.

 

[wristpin]

A thank you to all replies and suggestions. Motor up and running.
The product of over greasing the top bearing had got very sticky in the cold weather and was gumming up the centrifugal start mechanism.
Back in business, thanks.