I had a really strange issue today. I went to check out my local Guzzi dealer but when I went to start the bike it would not engage the starter. The petrol gauge was showing very low, The switch was suspected so tried some WD40 to try to clean it with no success. The relay under the seat was operating. I planned to jump the starter to get me home but needed some fuel first. So I borrowed a fuel can and got 5 ltrs from the nearby garage. Having put in the fuel I thought I would try the starter again not expecting any luck but this time it started without issue.
Question is there a low fuel level or fuel pressure interlock that prevents starting attempts if either are too low?
My 2007 Breva 1100 did this occasionally but simply switching the ignition off and then on again seemed to sort it - something not re setting properly? I never did find out but it always worked
I had a similar problem but mainly when the starter was hot from a run, this was a sporadic problem and I found a quick fix was to use a “key” from a corned beef tin to bridge the starter solonoid conenctions (this did mean taking off the starter motor cover or leaving off for a while).
I stripped and cleaned the starter motor but that made no difference - replaced the starter motor in the end.
I didn’t have any problems after that but I gather the “startus Interuptus” fix (which I have now done) may well fix this problem