Modern Vespa

bought this bike been sitting for a year, 6,000 miles, fresh battery and fuel 1/2 tank. First started, ran poorly up to 3000 RPM then took off ran great, everthing below 3,000 was rough and enemic. Added Sea Foam fuel treatment, fixed rough, low power bottom end within 10 minutes. Next issue Key on, start run switch on, brake lever compressed, sitting on seat, bike will not crank, all lights on dash cycle through as expected, everything is perfect, except it doesn't crank. Cycle the ignition on and off a few times and it cranks just fine, after starting, at same moment will not fault again. After later stop, may or may not fault again, if so repeat key on off and it works again, continuing to press the strart button has no effect when fault appears. I was thinking faulty ignition switch, but it sees to get better every time I use it, maybe a start relay?

Has anyone encountered this problem. bought this to run the 2023 Scooter Cannonball, would hate to have it finally crap out in Kansas if you know what I mean.

Ideas.

I'd replace the starter relay. Do the easiest and cheapest first.

Do your brake lights come on when you pull the brake lever to start up?

My bet is on the ignition switch - a very common failure point if the fault is intermittent.

I am betting with madison on the brake light switch faulty.

which brake lever are you using? try the other one. check to ensure the brake lights work with each.

that switch is high VERY common failure point. best to ALWAYS carry a spare.

I had a failure very similar to the one described and it was the "antenna" of the ignition switch that did not read the key correctly intermittently. I replaced it from another Piaggio for test purpose and it was perfect, I bought it and it hasn't failed anymore.