t140v electrics

[thunderace1]

Happy New Year to everyone 

I have just returned to working on my t140 (too little free time last year) and have started on the wiring.

I have managed to get everything to work with a little bit of playing with (lights, indicators, horn, brake lights including the tricky front brake switch) but I cannot get any joy at the sparkplugs. My bike is a 1978 t140v (pre electronic ignition etc., positive earth) but I have fitted a Sparx electronic ignition kit, 2 6v coils and new plus leads - I have also made sure that the cut off switch works correctly .

Tracing it through I have ~12v coming off the main loom at the 2 linked Yellow/White wires which I have connected to the white wire of the sparx ignition box but I only get ~3v out of the sparx ignition box via the black wire that I connect to the -ve terminal of the left hand coil. Where has the power gone and presumably because the coil is only getting 3v this is the reason why I am unable to generate any sparks.

Before I replace the ignition unit is there anything that I have missed or just got wrong?

Thanks

Mark

[wetdog]

have you wired the coils  "in series"

[thunderace1]

Yes as per the Sparx wiring diagram.

Best regards

Mark

[wetdog]

"in series" is for 12v application , if using 6v positive earth (I think t140 is) coils are in parallel  , ie black to both neg and red to both poss on coils . this is how it worked on my t100 .

[L.A.B.]

if using 6v positive earth (I think t140 is)

"is...."


...6V? Positive earth? Both?

Hopefully you meant "if using two 6V coils in a 12V +ve earth (a 1978 140V is 12V +ve earth) electrical system" ?

However,

ie black to both neg and red to both poss on coils . this is how it worked on my t100 .

Not recommended for a 12V T140V. Hopefully thunderace1 has in fact, wired it in accordance with the Sparx fitting instructions (coils wired in series).   

[bikerbob]

I don't know about Triumph's but I have a BSA A65 with a Pazon system fitted which is similar to the Sparx unit and I had a similar problem and it turned out to be a dodgy coil replaced coil and everything OK. I was put off thinking it was the coil because firstly both coils were only 15months old and secondly both plugs were not sparking but having tested both coils one was faulty. Do not make the same mistake that I did in assuming that the ignition  module is at fault without testing everything else first. One of the best things that I bought was a quite cheap multimeter which enabled me to check both of the coils and also the trigger unit. It does not allow you to check the ignition unit however, I contacted Pazon and they informed me that this could only be done by them. You could try to contact Sparx and see if they provide a fault diagnosis sheet I know Pazon do and It is very helpful for locating possible problems.

[wetdog]

wish i could remember as it was only about 7 months ago , ive droped the bike on the isle of wight for this years summer run about (will look when im next there) im 99% sure i wired it parrelel but may have used 12v coils as these where arlready fitted and i dont remember changing them , the system came from wassel (pal system) and the bike ran well .

[bikerbob]

Copy of Pazon instructions for Triumph BSA and Norton twins.

[L.A.B.]

im 99% sure i wired it parrelel but may have used 12v coils as these where arlready fitted and i dont remember changing them , the system came from wassel (pal system) and the bike ran well .

I don't know anything about a PAL system, but the majority of currently available aftermarket wasted spark electronic ignition systems such as Sparx (which is the system in question) also Boyer Bransden, Pazon, Tri-Spark, VAPE ignition (currently sold by Wassell) must have 2x 6V, or 2x 12V coils wired in series. Some makers (Boyer, Pazon) say that two 12V coils wired in series may give adequate performance, but recommend two 6V coils are used. Connecting coils in parallel with these ignition systems is not recommended* as it will eventually destroy the amplifier box.

 


http://www.tri-corengland.com/acatalog/Sparx_Electronic_Ignition.pdf
http://www.boyerbransden.com/pdf/KIT00052__BOX00023_.pdf
http://www.pazon.com/files/PDF/PA2.pdf
http://wassellcarb.com/images/Ignition%20instruction.pdf


*One exception being the old Lucas RITA electronic ignition.     

     

[wetdog]

best look at this next time im there , the bike is running well but maybe not for long , good job it where it is , did the lucas system not use 6v coils , what does it do to the amp unit

[L.A.B.]

did the lucas system not use 6v coils,

Yes, the Lucas Rita can use 6V coils in series (3x 4V coils in series can also be used for triples) however the various Rita applications and coil options does become somewhat complicated and it isn't relevant to this topic, further discussion of the Lucas Rita I feel would only serve to cloud the issue.               

what does it do to the amp unit

Sparx, Boyer, Pazon etc, ignition boxes usually have a maximum current capacity of around 5 Amps.

http://www.tri-corengland.com/acatalog/Ignition_fault_finding.html


Boyer Bransden:

3) The maximum ignition coil current through the unit must not exceed 5 amps.

According to Boyer Bransden's Technical Dept., if the coils are connected in parallel, then: "...the system will draw too much current"
http://www.accessnorton.com/coil-selection-t7982.html#p83925


Pazon:

Maximum Ignition Coil Current Draw: 5 Amps

 

[wetdog]

interesting , im surprised that two 12v coils in parralel draws over 5 amps , but will take a good look and alter when next there (easter) . the bike runs all ok but this looks like being short lived thanks