I keep 2001 ET4 on a trickle charger when not riding. Ride at least 1-2 times per week, put on 2300 miles in last year. Most of the time, after a few days not riding, takes 5/6 sometimes 7/8 cranks to start. Understand this is an issue without fuel injection and with older ET4s. Last 2 times, it cranked 2-3 times then this winding sound. Put back on trickle for 5 minutes, started. Now I get 1 crank, and won't start at all. Trickle indicator shows green Maybe bad battery, starter, spark plug, all above? Taking in for service to Vespa Motorsport (Robot for those who know) but any ideas? Love to ride and don't want to get stranded not starting. Do the crank starts even work? Mine seems very flimsy.