Read this viewtopic.php?f=1&t=173&hilit=better+cranking .

Is it a good idea & possible to do that on the 907?
An how to do it then?

Is it as simple as this:



?

Gert,

I assume you mean more "power" [volts] to the coils???

jslocum's post discovered the potential loss in the wires to the coils (down to 9.2 volts).
I can't really work out what the diagram is trying to do - how can a relay do anything but switch? the circuit must also shorten the path from the supply [battery] to the coils.
I suppose it does eliminated the loss from the switch...
to get "less loss" you need to shorten the wires..or go larger diameter.

In my old Chrysler I had a ballast resistor and 6 volt coil - the car "ran" at 6 volts.
for starting the switch eliminated the resistor and supplied 12 volts to the coil on starting (and a big fat spark)

the 907ie has the ignitors that power the coil for spark duration & spark timing.
it's unlikely that you can get more power to the coils...I expect it will be close to optimum for starting at 12 Volts anyway.

By doing so you reduce losses to a minimum. that's true but not the best remedy.
A better way to "juice up" the cranking power is to check every contact for corrosion and proper working. Pay also attention to cable shoes/cable of the starter lines.
As the copper fibres rather thick they tend to break just after the cable shoes due to vibration of the bike. this happened to me. I replaced all the lines to the starter moter and back from the engine casing to the battery by 25 mm2 welding cables. These are extremely flexibel.
Also look to the rubber part containing the starter relay. the way mine was mounted it was like a bowl containing water ( and corroded contacts)
When you have a few bad spots/contacts the voltage drops under 10 volt and you won't get a spark.

ducbertus

You dont need such mod in 907 at all, if Your wires and groundings are in good condition... 750 Paso need such relay to coils, but NOT 907... 750 Paso have much smaler diamter wires, than 907 and thats why!

OK, thx!