Join Date: Nov 2011
Location: Southeastern PA
Thanked 22 Times in 21 Posts
First thing is check the battery terminal connections -- pull them off and clean them (my first thought with the gauges sweeping was a loose connection). Then the connections to the starter and the main ground-- you'll need a service manual to find them. After that, you're looking at difficult electrical diagnosis. I'd begin by wiggling the wires leading to the ignition switch barrel -- if it turns off and on it could be the barrel or the power feed to the switch -- I've seen or heard of both. Actually, go straight from the battery to the barrel as it's easier to check. Good luck.
And 40k is not a lot for the motor; it's the chassis that needs looking after at this mileage.
'61 Clubman's Gold Star, '13 Duke 690, '13 Daytona 675R (track bike), '17 Superduke GT, '18 Street Triple RS