Forum

[NicoV]

If your battery is empty, you can still start your Bullet if you have mounted a capacitor (elco of a fairly large size) across the battery.
Is that also the case if you have installed a Boyer electronic ignition ?

[Alan R]

Hi NicoV-------not quite sure just what you have in mind here....A capacitor is not quite the same as a battery in terms of storage and discharge behaviour..........Why not ask the guys themselves ?? --------------> -------------> --------- > http://www.boyerbransden.com/ --------

[Valsp]

I found that with on Intercepror with Boyer ignition it did not start when the battery was below 10 volts even though the capacity was new

[Adrian]

Ah, now WHICH version of the Boyer ignition kit do you have?



The Mk3 analogue is notorious for not working well with anything less than a full 12V supply, if it's not 100% it can go full advance and cause the engine to kick back on starting. By not starting at all on Valsp's bike it sounds like it in fact saved a load of trouble!



You might get a Boyer to run with a capacitor instead of the battery IF:



1. The alternator is in really good condition with no loss of magnetism to the rotor (consider an alternator upgrade if necessary);



2. You have the later Mk4 Boyer with a TCI box that is supposed to be more tolerant of less than the full 12V than the Mk3. A Pazon ignition also claims to work better in this regard than the Mk3 Boyer. Pazon was founded by ex-Boyer staff.



A.

[Revband]

Putting a capacitor in parallel with the battery won't work either way, any voltage given out when kicking over will disappear strait to the battery and not reach the coil, a capacitor should be used instead of the battery, some bikes had an emergency start position on the switch this put the ingition on and disconnected the battery to overcome the problem.

[Rasp]

I've fitted a 'Lucas Rita' electronic ignition as used on late Triumph twins and Commandos to my Constellation. I was advised to fit a capacitor in parallel with the battery to improve starting when the battery is low. The bike starts well with good or poor battery or no battery.

[Alan R]

'morning all........When I first read the question from NicoV I took it to mean using an Electrolytic Capacitor ( hence the words "elco" and "of a fairly large size", whatever that may mean ?? )---to act in place of a fully discharged (or "Empty" ) battery to power a starter motor which Bullets now have fitted..( What model Bullet is it please ??).......Surely if "you have mounted" an Elco across (ie..in parallel) the Battery terminals that would act as a short circuit ??...........Agreed you have Capacitor starters fitted on strip lighting and some induction motors but that is for electrical starting and not a physical form of starting..............I suspect you guys are on the right track (?) anyway but I think it would help if NicoV would come back and just clarify the request....


high res image upload

[Adrian]

Hi Alan,



I think you have the wrong end of the stick! NicoV's question is clear enough, he simply wants to know if using a capacitor as a battery eliminator will still work if the bike has a Boyer Bransden electronic ignition installed instead of points ignition. No mention of electric start, as this is obviously(?) a kick-start only option! If the alternator chucks out enough juice at kick-starting revs you don't need to have a battery, just the capacitor. We know this works on 12V points-fitted bikes with an strong enough alternator as Lucas used to sell their 2MC capacitor for this very purpose.



BUT if the bike has electronic (TCI rather than CDI) ignition fitted, which can be a lot fussier in terms of required voltage, will this STILL work?



The answer to this depends on how good the alternator is and/or how tolerant the TCI box is of lower voltages.



For more on the use of capacitors as battery eliminators have a look here:



http://www.rexs-speedshop.com/epages/es ... oducts/BE1



http://www.rexs-speedshop.com/epages/es ... oducts/BE2



Our hosts don't list them in their accessories but they DO sell the Boyer Bransden Power Box, which is a reg/rectifier with the capacitor built in.



A.

[Valsp]

Adrian you are spot on, its the older Boyer.

Its only since I replaced the complete alternator and fitted an electronic voltage regulator and new battery that it now starts and runs really well

How nice it is not to have to worry if its going to start when its time to go home from the cafe!!

[Alan R]

Hi guys-------Thanks for all that info ADRIAN and duly noted......Just for interest sake I used a CDI set-up on my 250 Bultaco and 350 Montessa Grass-Track bikes back in the 1970's,( Southern Centre ACU--Tadley & District Sporting Motorcycle club ) and very good it was too !! ( But on the odd occasion it seemed that spurious infa-red daylight would upset the exposed trigger head )....My entry-level old BSA C15 was fired by on-board battery and points and electrically was subject to reliability problems due to heat and vibration......

So with NicoV's battery now removed ( Eliminated ) will his lighting system have to be converted to direct feed ??......