Race bike Custom Wiring question

[1down5up]

Quick question for the more Electro talented here on wiring for my Race Bike (round head Tonti Guzzi - but prob relevant to any bike)

How much current do the coils pull on the primary winding side??

Can I run the coils straight off the kill switch (i.e. activating the kill switch cuts power to the coils directly) - or - should I use the kill switch "on" to activate a relay to bring in power to the coils

not sure if the generally smaller wire found in the handlebar controls is sufficient.

[Old Jock]

My LM 1000, square head (I'd imagine the round heads are the same) ran the supply to the coils directly through the kill switch as OEM.

That said what sort of switchgear are you using? The older round head swtichgear was........well pretty crap TBH.

The current taken by the coils is dependent on the coil resistance, lower the resistance, higher the current pulled.

Guzzis don't usually need low resistance coils, but you may run them as your bike is used for racing, so you could be pulling a higher current than usual.

Personally I'd run them through a relay, on my LM1000 which is only used on the road with a Sasche ignition, the kill switch opens the supply to the electronics which kills the ignition circuit.

[pressureangle]

I wired my '85 LM1000 through the killswitch, as stock- with updated switchgear from a reliable source. The start switch disintegrated and upon inspection I discovered that the ignition feed wires had been hot enough to melt the insulation and stick the wires together, though not yet to ground failure. I installed a standard 30A relay to feed the ignition. It has a dyna setup with black 5ohm coils.

I raced flat track and roadraced for 20some years. I can say that switchgear failures are very, very common and having a relayed ignition circuit would have prevented 2 or 3 DNFs for me personally over the years. If I was building a new racer, and the rules allowed it, I would probably run the ignition relay power through a heavy toggle, use the normally closed circuit and run the ground side through a dead man's cord on the bars.

[g5guzzi]

standard Guzzi coils are 3 ohms each and when used
with Dyna ignition use 7amps when running and 8amps
when  switched on not running.

Malc

[1down5up]

I wired my '85 LM1000 through the killswitch, as stock- with updated switchgear from a reliable source. The start switch disintegrated and upon inspection I discovered that the ignition feed wires had been hot enough to melt the insulation and stick the wires together, though not yet to ground failure. I installed a standard 30A relay to feed the ignition. It has a dyna setup with black 5ohm coils.

I raced flat track and roadraced for 20some years. I can say that switchgear failures are very, very common and having a relayed ignition circuit would have prevented 2 or 3 DNFs for me personally over the years. If I was building a new racer, and the rules allowed it, I would probably run the ignition relay power through a heavy toggle, use the normally closed circuit and run the ground side through a dead man's cord on the bars.

Great info, thanks - exactly the thing im trying to avoid.

Relays it is