O/T Lawnmower solenoid

[Alex Wong1697456877]

I've recently bought an old Countax ride on mower (A20/50)

 

It seemed ok but after stalling it, it wouldn't start again. I got the usual machine gun rattle and guessed the solenoid was knackered. Assuming I bypass the solenoid, it should turn the starter motor, shouldn't it?

 

I tried shorting the two terminals on the solenoid and got the hissing sound of a wire shorting out. Why is this? I thought the solenoid just joined these two together? What have I got wrong here? Do I need to remove the solenoid from the circuit completely to test the starter?

 

Thanks!

 

Edited by - Alex Wong on 5 Nov 2007 11:10:42

[Sheds Moderator]

Machine gun rattle may just be a weak battery which is unable to hold +-12V when the starter motor is under load, so the solenoid can't stay open against the internal spring, so it disengages, so the voltage rises, so the solenoid reengages, so the starter fires, dropping the voltage, and the whole thing repeats itself.

 

The switched current is VERY heavy, any bridging cable needs to be jump lead quality or better. Sorry if this is Granny sucking eggs territory.

[Foxy Smith]

Alex, two comments to make 1. The pinion on the starter motor on these machines are buggers for coming undone. You will get a haorrible ratcheting noise and engine won't turn over. Can be an easy fix, but you will probably need to turn the pinion upside down when putting it all back together. 2. I use a Banner battery (my spare one for the seven) on the lawnmower. This can be very handy!

[Alex Wong1697456877]

The bridging cable was the two prongs of my needle nosed pliers. I also tried a jump lead but both caused a hissing noise, like you get when a wire starts to burn up - but none of the wires felt hot to me. The battery charge seems ok but will try jumping it off my old mower. Do these things have an alternator of some sort? (20Hp Briggs and Stratton V twin)

 

The pinion looks ok - had the cover off and checked that.

[Alex Wong1697456877]

BOSS,

 

You were absolutely right and you're explanation makes perfect sense. Dispite the battery light being on (indicating adequate charge on a Countax), charging the battery overnight has helped.

 

I guess I need a new battery. Is there a simple way of checking the charging circuit (alternator/rectifier etc) on the mower? I guess if I see 14V when running and less when not, it's probably working?

 

Alex

 

PS I absolutely love this thing - it's mulched it's way through wet overgrowth with absolutely no hesitation, unlike my Honda ride on mower which would jam just with the slightest hint of damp grass.

 

Edited by - Alex Wong on 6 Nov 2007 11:04:17