FYI: Right after tidying up a lot of electric wire I got problems starting.
The starter motor engaged but gave up just as the motor startes turning. Just short of starting the engine. (and my engine fire very easy)
It was no lack of power but a cut off.
Instrument light and head lights went on for a short blink.
After first try it often failed another attempt, no reaction, for a while.
Battery were good, started fired the engine right up shorting over the relay.
Many hours of fault tracing and the problem were found.
Failure reason: Bad ground on the starter relay.
Fix: New wiring with silcon/multiStrand wire from relay to main ground connection on frame.
Same ground were also fed into the faulty ground wire that went into the main loom.