Modern Vespa

Hi, my Vespa has this symptom where it has a momentary loss of power upon acceleration.

When it first started happening I did research online and some suggested that it may be a dirty air filter blocking air flow. Since I had never cleaned the air filter I thought this could have been the issue. I cleaned the air filter, which was pretty dirty and thought this was the problem.

The momentary loss of power continued to happen. Then all of a sudden, as I was traveling on the freeway, the Vespa completely cut off and the engine cut off. The Vespa was towed to the dealership where they changed the cap on the spark plug and the engine would turn on.

However, the momentarily loss of power still continues. Imagine accelerating and then a split second the acceleration stutters, almost like a hiccup. I've noticed that this only happens after about 20-30 minutes of riding, if it is a short ride of less than 20 minutes, i won't experience it.


Does anybody have any idea what's going on? I've been hesitating taking the Vespa out on longer drives for this reason and has really put a hamper on my enjoyment.

Could be a dodgy kill switch.

Hi

I had the same issue with my GTS300 super sport. After having the ht cap checked and a full service the issue remained. I then heard about a remap of the ECU being available and had this done 2 weeks ago. Since then the issue has not recurred. This may or may not be related to the remap but so far so good. I would advise you to check with a dealer if this might work for you.

Good luck

WD

I had that problem. It turned out to be a faulty fuel injector.

It took the dealer quite a few attempts to diagnose since it was intermittent. Finally the ECU kicked out an injector fault code. Installed a new injector and that was it.

Initially it was thought the culprit was the plug or HT lead or cap.

.....had a new fuel injector installed problem gone.

Another vote for fuel injector. I suggest you physically check it.

I had the same thing going, and it only got worse as the electrical connections on it deteriorated due to flexing and vibrations.

Here's a link to a picture of it.
Hiccups/ Hesitation/ and free lift to the office.

Steve..