Hi,I have a 1965 B40 which is a problem to start but runs perfectly .I bought the bike which came with a Boyer inductive discharge kit NOT FITTED.I have fitted this kit but it tells me to disconnet the condenser but the lead to the coil & the cb spring is attached to the condenser...Any idea if you need to disconnect ?There is a decent spark but no better than the standard system .
If the spec says remove the condenser, remove the condenser.
Hi Brian,
These systems work by changing the way that the points trigger the coil switching.
In the standard configuration, the points switch power directly to the LT side of the coil. There is a fair current drain and this produces a spark at the points when they open. To reduce this arcing (which damages the points and causes radio interference) a condenser (capacitor) is fitted across the points. The body is grounded and the single wire usually has a fork or loop connector that goes onto the same threaded post as the wire to the coil. If it's the fork type you only have to loosen the nut(s) and pull it to disconnect which makes things a bit easier.
With the BB unit connected, the points just switch some low current logic in the unit which then in turn switches power to the coil.
This offers a 'cleaner' and more precise switching with no arcing at the points and often results in improved running, particularly when idling.
The condenser (capacitor) is no longer required in this configuration and as it also has the effect of 'smoothing' the switching operation is best removed - this gives a sharper and more precise trigger to the BB unit so is worth doing.
If you don't notice a big difference then it probably means that your bike was already running well with the standard configuration.
Cheers,
Bernie
Sorry ,I obviously didnt explain properly.The condenser is an integral part of the cb set up having a threaded part onto which the wire to the coil & the cb return flat spring is screwed therefore it cannot be removed,if it is then the points wont open /close
So it is - just looked at the part online. That makes it a bit trickier as you'd either need to isolate the condenser connection(s) somehow or make up an insulated replacement - which wouldn't be trivial to do.
Is it really worth it if it runs perfectly? Your starting issue could be something separate - maybe you need a new condenser! :o :o
Thanks for the input.The condenser & points are new,just thought I would try this kit .It is possible that there is another issue,I reset the valve clearances last night & it started a bit better .There is no valve lifter so the effective stroke of the kick starter is a bit variable .At 77 years old I probably need a new leg .
So this is a trigger set rather than replacing the whole set up? If so, it belongs in the bin...it will be no advantage over the original set up.
Probably best to add a valve lifter to make starting easier.
The advantage of the ignition fitted is the low current through the points needed to trigger the current to the coil, as explained by beriej.
In the pic, the red line is what would be ideal, a regular and clean on/off. With points it will never actually be that good due to the mechanical limitations, bounce, arcing etc but that's the goal.
Adding the condenser changes the voltage behaviour to more like that in the blue line so instead of a clean switch between 0V and battery voltage and back it's a rise and fall instead so the point on the curve where the coil fires depends largely on the coil itself. That isn't necessarily a problem as long as it's consistent and we time the ignition to the spark using a strobe but it means static timing using fag paper or multi-meter might not be so precise (although usually good enough with our road bikes).
One other advantage of the electronic trigger systems is that they switch the coil resulting in a much cleaner make/break, more like the red line. That clean voltage switch can result in the coil discharging more effectively and producing a stronger spark.
Cheers,
Bernie
I was under the impression the valve lifter was also there to prevent excess loading on the kickstart assembly when starting.
Using the valve lifter means that you are using the inertia from the flywheels to turn the engine over, not the kick start assembly.