So the wire that passes insufficient current for that very brief period, is the smaller wire that connects to the solenoid with the spade connector?
Sorry, if this is a stupid question, just want to make sure. Electrical stuff has always been a bit of a challenge for me to understand.
Yes thats correct but on the bikes with the relay fed through the switch it's just as likely to be that.
This is what I found on the 07 Griso
I thought I would investigate the new to me 2007 GRiSO to see if it would benefit from the Startus Interuptus fix.
I was surprised to find the start relay fed direct from the battery, not through the ignition switch, this IMHO is how every Guzzi should be wired.
But on further examination I found the tiniest of wires from the relay to the solenoid. I knew it would benefit from a larger wire but thought I would document the improvement
I do this by measuring with an oscilloscope the peak current into the solenoid and the time it takes for this to drop down to the holding current
I measured this time and I find the solenoid pulse lasts for 50 milliseconds while the solenoid current peaks about 22 Amps which is ok but not great I suspect this is barely over the point Startus Interrupts takes over and the solenoid just sits there
So then I upgraded the wire from the relay to the solenoid. The current pulse now lasts only about 15 milliseconds, less than 1/3 as long telling me the solenoid is operating at three times the speed it was before and the current peaks just over 30 Amps. Eight Amps doesn't seem like a lot but 3 x as fast, you can't knock that.
Note: This current I am referring to is not the cranking current, it's just the current into the solenoid.
I have a storage scope but it's quicker just to sketch out the trace. I drew Before and After on top of each other for comparison.
You can see what a huge difference it made when I replaced Luigi's little bitty wire (Red Trace) with an 18 gauge wire (Green Trace)
Let me say again, this is not the starter motor current, it's just the current going to the solenoid coils.
It stands to reason a faster solenoid is less likely to hang up giving you the dreaded click.