Modern Buddy

Internet experts, help me diagnose an issue with a new to me Blackjack.

Our scooter seems to hesitate on acceleration until it is warmed up. It "chugs" while holding the throttle steady. Opening the throttle seems to help. As it warms up, this goes away.

We purchased the scooter in June, and it is sitting with about 5800 miles on it now. It seems to be getting slightly worse as the miles pile on.

Per the records that came with the bike, the carb was serviced and the auto petcock fuel valve were replaced by the dealership (Vespa Portland) in November of last year at 5400 miles.

What should I look into to address this issue?

If the scooter has only had 400 miles put on it in ~10 months there is a chance the carb needs to be cleaned again. You may even have old gas in there.

I would get some Seafoam or other additive and add it to the tank, then run all or most the gas out of the tank then refill it(again adding Seafoam.) If you are lucky this might solve your problem.

If that doesn't help I would clean the carb and check the spark plug and air filter.

I've had similar symptoms due to a partially clogged pilot jet. Seafoam can work sometimes but carb removal and cleaning is fairly easy to do. The jet orifices are tiny, especially the pilot jet, and it doesn't take much to clog. If you take the carb apart you can clean the float bowl and passages of any debris or corrosion. Some carb cleaner, guitar strings and an air compressor are helpful.

Thanks folks, I'll try some Seafoam first. We've never had any issues with our Buddy 50 carb clogging, and it is ridden fairly sporadically as well.

Seafoam did the trick!