Modern Vespa

ssue with Vespa GTS 300 2010: Power Loss and Engine Shutdown with Passenger

I've got a 2010 Vespa GTS 300 that's been well maintained by a specialist. Recently, I've encountered a couple of problems:Cold Start: It takes a lot of effort to start the engine in the morning, requiring three tries before it cranks up.

After Maintenance: I replaced the spark plug and cleaned the fuel injector, and everything seemed fine. However, today I noticed a new issue while riding with my girlfriend (who weighs 60 kg).

After about 15 minutes of riding, I lost power in the throttle, and the engine turned off. After letting it rest, the engine started again, but when my girlfriend got back on, it shut down immediately.

I rode the Vespa home alone without any issues, but when we tried again with her sitting on the back, the engine shut off, and this time it misfired and wouldn't go past 30 km/h.

Has anyone experienced something similar or can help me diagnose where the issue might be? Any advice on what to check or focus on would be greatly appreciated!

Next time it stops turn it off and turn the key on and listen for the fuel pump to prime it maybe the fuel pump.

The issue with carrying your pillion passenger is probably the fuel injector. The injector sits directly under the seat and the extra weight from your girlfriend might be causing the seat to touch the injector causing it to malfunction.

My large friend had the same problem. Too much weight on the seat broke the fuel injector

Im experiencing the same thing. First rough running then No start. I ordered a new fuel injector on amazon on the link.
$20. Will see if this solves my problem.