Modern Vespa

She's got just under 4000 miles and is making a cyclical whirring noise between 35-45mph, like WHIRR (1 sec) WHIRR (1 sec) WHIRR. It's never done this before, any ideas on which type of adjustment needs to be done?

Sounds like a slipping thromdibulator. Or maybe the spiggletiser nut needs adjusting...?

Best,

Mark

Are you pulling your left brake handle when you hear the sound?

I wonder if it is the fuel pump. You can hear it priming when you first turn the ignition on.

The regular pattern of this repeated whirr makes me think of gear cogs getting into a specific constellation toward each other, with one having wear that causes the sound. Or any other moving parts interacting with others that need a specific constellation to cause the sound.

Or a warped brake disc/loose back wheel..

No...its the Muffler Bearing is counter rotating against the left-hand-smoke shifter and it's creating a sonic imbalance.

Is your scooter still in warranty?

Best,

Mark

It's probably your fan. Do you notice it when you're stopped or moving slowly vs. going at speed? The sound can be disconcerting the first time you hear it if you're not used to it.

+1. That would have been my guess.

Fan running briefly, then off for one second, then on again and repeat of the same? If the fan did this, the thermostat would be defect.

Thats the sound of money being emptied from your pocket.

Hey, guys, the OP is a first time poster and has a legitimate question. All the off the wall answers don't help. Can we try to be a bit more serious here?

I would have to agree with you if it did this consistently but in terms of the OP question, I can't think of anything else that would make that sound. I know it scared the bejebus out of me when I first heard it and thought it was some wrong with my scooter. (Although mine didn't do the run briefly then shut off and run briefly thing again)

The fan makes a cute kind of whirr, its little like the fan in a computer. I only ever hear mine when stopped at the lights on a hot day- I wouldn't hear it at 60-80km/h.

Are there any other symptoms? Changes in temperature perhaps? Oh, do you have Sava tyres? They can whir at about that speed, especially just off straight ahead. And they're rubbish.

just a 1 time poster it looks like .

...on the fan thesis: I am a brandnew GTS300 Super driver. I didn't even know there is a fan in the machine. When I heard the WRRR sound, while waiting in a lane, I thought it was the car before me making the noise, until I heard it when on my own. The sound is clearly longer than 1 sec, as described, so indeed it may be a thermostat problem. I am still riding in (600Km/400Miles) and was wondering if it is normal that the fan is necessary in rather normal conditions.

The fan will kick on and off at different times to help cool the antifreeze in the radiators/ thus cooling the engine. If you are sitting in stop and go traffic on a hot day you will hear it a lot more. Completely normal. It is just doing it's job properly.

Thx VEZPA for the clarification!

Aloha and welcome to the forum. A lot of people weren't told about the fan when they bought scooters that have them and it's perfectly reasonable to be concerned when you hear it. Better to ask questions when you don't know than to ignore something and end up ruining something. Would love to see some pics of your scooter sometime. Enjoy that new scooter of yours

Did you ever even read and comprehend this:

"making a cyclical whirring noise between 35-45mph, like WHIRR (1 sec) WHIRR (1 sec) WHIRR"

And if you did, do you really think this is normal? Then, maybe, your scooter has the same issue as the OP's

+1 It's getting kind of snippy in here...