Modern Vespa

I'm new here so this topic may be old for some of you. Ever since I replaced the battery in my 2016 BV 350, it hasn't idled properly. As you know, there is just a narrow band of RPM between stalling and the clutch starting to grab. That band is where it normally idles. I don't understand how a battery change can effect the idle unless it affected the mapping somehow. It's still rideable if you tweak the throttle ever so slightly keeping it just out of clutch operation though I'd rather not have to do that. How can I get my old idle back ?

Take you battery to an auto parts store and have it load tested. You can also run some jumper cables from a car to your scooter battery and see how it idles with a jump. This will tell you if its your battery.

If its not your battery I would check your voltage regulatory and after that take it to a dealer for a remap of the ECU.

Its fuel injected so you are looking for something electrical most likely.

read this thread

BV 350 battery replacement and other stuff.......

Did you overfill recently? Did you open the gas cap to relieve the pressure? Have you removed the Evap crap?

BV350 engine problem (uneven idle, popping, no acceleration)

Here's one of many that popped up when I searched BV350 idle in message title. You can also search with BV 350. Sometimes people put a space between the BV and the 350 but I'll let you search that one

Took it to the dealer......he re-flashed the puter and all is well again. Next time I change batteries I'll have jumpers from the truck keeping a constant 12 volts on the system while I do it..............

I changed my battery in Scoot Life after you started this thread, no problem. IMHO the BV350 ECU is the is the weakest link. My commuter is on it's 2nd ECU and will not run properly if I disconnect the Malossi fuel controller. Still runs like a scalded dog anyway.