S3 with no spark.

[Neil G]

Hi, took the S3 out for a quick run yesterday, all went well ( for the first few miles ) then I pulled over for a quick visual check ... I blipped the throttle and it cut out. Diagnosed no spark roadside so called ‘er indoors for a lift home. Still no spark so wondered if anyone has a logical 1 2 3 of checks I should do ?
Bit about the bike :-
New battery showing 12.7 volts
Main fuse good
Got voltage on the LT side of coils
I fitted one of those all in 1 reg / rec’s recently as the original reg had a broken terminal.
Bike is fitted ( when I got it ) with Boyer ignition ( labelled KH250 incidentally) which raises another question re timing which can wait until I get my spark back ...
Any ideas guys ? Limited understanding of resistance etc but have a good meter and willing to learn !
Cheers guys

[SAM]

Boyer ignition ok for s3. Timing same 2.6mm btdc.

[Treeman]

Possibly a bit too obvious, but check your kill switch has not been knocked?

[Neil G]

Boyer ignition ok for s3. Timing same 2.6mm btdc.

Cheers, just can’t see any timing marks that remotely line up when set at 2.6mm BTDC ? Will post a pic when I have got the lac of spark sorted.
Out of interest is there a particular cylinder you set the DTI up in ?

[Neil G]

Possibly a bit too obvious, but check your kill switch has not been knocked?

No, kill switch in correct position but worth checking out the wiring I guess ?

[SERPICO]

Got a Boyer on my S3 from memory timing as per usual marks for points but I can dig out fitting instructions if you haven't got them let me know on 07392072749.

Boyer need a good battery to work but if a sudden failure on all 3 suggests to me either a total failure of the boyer unit or a wiring connection problem from the Boyer if battery charging OK. Have you tried jump leads from your car battery to see if it will start?

[Neil G]

Got a Boyer on my S3 from memory timing as per usual marks for points but I can dig out fitting instructions if you haven't got them let me know on 07392072749.

Boyer need a good battery to work but if a sudden failure on all 3 suggests to me either a total failure of the boyer unit or a wiring connection problem from the Boyer if battery charging OK. Have you tried jump leads from your car battery to see if it will start?

Thank you, no I did not get instructions so a copy would be great, thank you. Weirdly the Boyer backplate states KH250 .. is your the same or S3 / KH400 specific ( guess it does not matter ? ) Good point re battery, I’ll try jumping it & see what happens, I did put a meter on it and it’s reading about 12.6v
Thanks for your help
Neil

[SERPICO]

http://www.boyerbransden.com/pdf/KIT00062.pdf

Fitting instructions here

[Neil G]

http://www.boyerbransden.com/pdf/KIT00062.pdf

Fitting instructions here

Thank you, very useful. I have got to the bottom of it ! One of the coils on the stator had failed ...Two of them gave the correct resistance on one was open circuit ... this caused all of the plugs not to spark ... new stator acquired from Boyer and all is good ... phew !!