Modern Vespa

I have a weird thing happening with my 2006 GTS250 while on my freeway commute. The bike feels fine with good acceleration but once I'm on the freeway and cruising I can feel a blip of power loss and then it comes back? This can happen a couple of times on my 10 mile journey and is extremely nu-nerving as you can imagine.

About the Scooter, 2006 with around 17,000 miles. I thought it could be the spark so I changed the coil, HT lead and plug. I also opened the transmission changed the belt (about time), added Dr Pulley 10g sliders (great btw!) and scuffed the bell housing.

None of these fixed the problem, where should I look next?

Thanks for any help!

-Kav.

Are you at WOT at the time? It could be the rev limiter kicking in. It happens on our 300s on flat or downhill stretches with the wind behind.

Not always at wide open throttle when it happens but I will keep that in mind on the next few commutes. Any other ideas Jim?

Cheers

-Kav

Only a non-optimal spark plug/lead.

Certainly sounds like the rev limiter to me. Scared myself silly the first time it happened on my GT125

same thing started to happen to me. Does your engine light come on?

Make sure your battery cables are not arcing to the body of the scooter. Also check that the cables are tight on the battery.

No it doesn't come on

Which is another pointer to it being the rev limiter.

Jim,

in my case in happens throughout the entire power band...from acceleration to 65-80 mph cruising. A sudden drop in power...on and off. It can go on for a few min and then stabilize to normal. Engine light just started to come on recently. Before it was just the power drop. Do you still think its rev limiter?
10,000 miles BV500 2009/10.


Thanks!

Yours isn't the rev limiter - Kav's probably is. Completely different engines as well. Maybe you're losing one spark plug?

Mine has only 1 spark plug and it was the 1st thing I changed. Checked the battery wires, all good. Any other ideas?

On the commute in this morning the scooter started it's coughing behavior again. I was no where near the rev limit and it always seems to be once the bike is warm? I nursed it into the garage and check out the HT lead / battery connection and all were fine? Not sure what is going on?

Cheers.

-Kav.

Your problem likely is the spark plug cap and/or wire. First check to see if the spark plug cap/boot is securely screwed onto the wire. If that does not improve the issue, replace them both. They wear out under constant vibration, and the connection becomes intermittent.

KAV when my LX wouldn't start when it was warm and other problems, we did a bunch of things and then finally, after nothing worked, we swapped out the CDI and it did the trick. Luckily i had one in my LT 150 that we could use. Weird things happen when the CDI starts to go and i'm not saying this would be a fix but if you can get your hands on one try it and see if it fixes the problem. Haven't a clue what was wrong with my LX but all i know is that it's run well ever since. Good luck