How can I get my scooter to start consistently?

by Jeff
(Durham NC)

I have a 2005 Avanti 150cc scooter. Sometimes it starts, sometimes it doesn't. It's very unpredictable. When it starts, it starts right up and runs perfectly. But when it won't start, it's as if the kill switch is on; it cranks and cranks, but never even sputters.

Twice now I have started it in the morning and ridden it to work without any problem, and then when I go to start it to ride it home at the end of the day, it cranks but won't start (so I've had to get a ride home).

One of those times I went back to get the scooter with a trailer, and it started right up. The other time it wouldn't start, but the next day (after it was in my garage), it did start.

Because it's so hard to predict, I've just been leaving it in my garage and trying to start it once a day to see what happens. Some days it starts, some days it won't (and I'm doing the exact same procedure to start it).

It has an alarm system, and I wonder if maybe the alarm is overriding the start mechanism and keeping it from starting. I've been leaving the alarm off, but even then, it still starts sometimes and not other times. When it won't start, the starter cranks the engine just fine, but the engine won't kick in or even sputter.

Again, it's like the kill switch is on (but it's not). One more detail, in case it helps. The scooter has a remote start (a button on the key fob). Just like when you use the key, sometimes it remotely starts right up, and other times it just cranks but doesn't start. It seems like an electrical issue since it runs great when it does start. Like maybe a loose connection somewhere.

But I've used the remote to start it (without ever even touching/moving the scooter) and sometimes it starts and other times it won't, making me think a loose wire might not be the culprit since the scooter wasn't moved at all between start attempts.

Any suggestions?