Modern Vespa

Hi all,

First time user here and first time Vespa owner. I've had a 2020 GTS300 for a few weeks now, got it with around 3,500 miles, and aside from a surprise ASR scare everything has been running well.

Except, that is, for when I hit real highway speeds of 75mph+, when the temp warning light comes on. As soon as I slow down it goes out, but obviously this isn't ideal for safe highway riding. This is the only time the light comes on and I'm a bit stumped about why that would be. Anyone have thoughts?

Thanks,

Chris

Have you checked the coolant level is between max and min?

^^^THIS^^^.

Also, if the coolant hasn't been changed since new, it's likely due. It's supposed to be changed every two years. It gets acidic after that and starts some internal corrosion as I understand. It's an easy, but a little messy, DIY job if you are interested. Look at YouTUbe videos by McBergsma and Scooterwest. Not a lot of tools needed and there's lots of MVers that will help answer questions on its procedure and parts.

Miguel

Does your fan come on when the bike gets hot and the temperature warning light comes on?

Though I envy the horsepower, sort of, this is why I like my air cooled 150.

Thanks, y'all. I checked the coolant, added a bit and will see what that does, but yeah, a coolant flush is probably a good idea.
And, I hear you about air cooled, this is my first water cooled two wheeler...loving it though.

About 5 years ago, I asked a Royal Enfield engineer why they chose to water cool their 650cc bike. He says every manufacturer has to water cool because it's the only way they can maintain the mechanical tolarances tightly enough to pass emission regulations. Most of us have never had problems with the water cooling systems on our bikes.

Best
Miguel

Going back to your first post.

It is a 2020 model and has run 3500 miles. That means it is quite new and has low mileage. There is no reason to expect a major problem.

You have it for some weeks. We are now end of February, so you got it probably early this year. I see you live in Santa Cruz. I expect moderate temperatures maybe 10 to 15°C, but certainly not hot summer temperatures. So there should not be any problem with the cooling capacity.

If you run the scooter at close to its max speed then the engine has to deliver close to its maximum power and needs maximum cooling. If the engine temperature gauge then goes up and the warning light goes on then it means there is not enough cooling capacity.

Or there is not enough water flow, meaning there is a problem with the water pump or the thermostat does not open fully or the water flow through the radiator is hampered by some debris.
Or there is not enough air flow, meaning the radiator front is clogged by dust and sand or mud.

So the first questions:

When you go at highway speeds, do you see the temperature gauge then gradually go up? Or is the light coming up while the gauge is still below the red zone?

Did you check the radiator is clean and there is no issue with airflow?

Also noise, the fins on the cylinder & head broadcast the noise, especially as the cc's & revs go up, a water jacket is a good sound dampener
The convoluted intake path is mostly to dampen the intake noise

I'm missing the connection to the OP's over-temp problem? Miguel

Yeah, I get it. Everything will eventually be water cooled for emissions. But, for now I like the simplicity of air-cooled. I am an old VW air-cooled Head, so it is just up my alley.

One less thing to worry about in my book. But, rock on, as long as it is a scooter, all is good.

Soon there won't be either...everything will be battery powered. I am on that already with a Honda CT90 EV conversion. Looking to the future.

Also, who needs 650cc? Not me. I can get by with 300-400 tops. Any more is just power lust.

Same connection as a 650 Enfield

There is a reason why a water cooled scooter such as the GTS lasts 2 or 3 times longer than an air cooled scooter, and will cruise all day at 70 mph.