Modern Vespa

Anyone know where I can order a lower temperature thermostat for a gts 300?

may I ask why?

I'd like to buy one.

fair enough.

Good conversation lol

What is a lower temperature thermostat? Lower than what, or lower how?

I rode a GTS all through the winter in Canada last year. It worked plenty fine. Sometimes when it gets cold it just flashes at you, as if to ask "Why are we doing this?" but, in the bike's defense, that's a fair question.

I was looking around a bit on internet and indeed lower temp thermostats are offered. Just as an example: https://www.engine-dynamics.com/Performance/pid106174/cid179/Low-Temperature-Thermostat.asp

Low temperature is then 75°C compared to standard 90°C. (75°C=167°F; 90°C=194°F)

One can ask: why? Looks like it is coming from racing.

It is suggested a low temp thermostat also could be useful in a hot climate.

The thermostat controls how hot the coolant in the engine gets before the coolant starts circulating out of the engine and through the radiator. Although you test a thermostat by dropping it into a pot of hot water to see if it opens, relatively suddenly, in practice the thermostat opens gradually and lets hot coolant dribble out into the radiator. If the coolant continues to heat up, the thermostat opens wider and wider, keeping the temperature needle steady at the thermostat's rated temperature, until full flow is achieved. Most of the time, even when it's hot outside, full flow is not achieved - otherwise the engine would be close to overheating.

The thermostat's designed temperature is a function of how hot the engine is supposed to run when fully warmed up. Lowering the thermostat temperature is likely to reduce engine efficiency and add carbon to the valves over time. Most liquid cooled internal combustion engines have 190-195° thermostats. I don't see the point of lowering that. Air cooled engines run considerably hotter, by design.

The sustained engine coolant temperature is intended to be no less than the thermostat closing point, but the upper temperature will be as hot as it needs to be until the heat generated by combustion balances the cooling generated by the radiator, which in turn depends on airflow and air temperature.

A lower temp thermostat will lower the engine operating temperature only under good cooling conditions i.e. sustained motion generating good airflow.

A lower temp thermostat will not for example prevent overheating in traffic, but getting the cooling fan to start earlier can help. I'm not familiar with the liquid cooled Vespas but it is not unusual to add a manual bypass switch to motorcycles to start the cooling sooner than the usual 100C that a radiator fan switch typically operates at.

Do malossi or poloni do a high performance fan?

I've added this to my gts hpe

lol.


There is an aftermarket fan to fit the right hand side radiator which doesn't normally have a fan. https://www.ruten.com.tw/item/show?21929131957470

ITS NOT RED OR BLUE. How can it be a performance item.

Also I don't see a southern hemisphere model. Does it use GPS to know which way to spin the fan?

ThermoSTAT not Thermo METER
My bad

Thanks for all the responses. Some really good information. I live in FL. Wanting to protect the longevity of the engine. I do like the idea of a manual switch. I did find a thermostat-

https://scooterpartsco.com/gts-300-engine-c-3637_3643_3804/thermostat-140-degrees-for-vespa-piaggio-aprilia-125300-p-36572.html

What I find is that it comes from racing.

The idea behind is that the engine temperature will reach a lower temperature on the sections of the track where the full engine power cannot be used, due to bends and so on, and that the engine can operate longer on the sections where it is pushed to the limit without risk on overheating.

In practice for us driving on normal roads there is no benefit, on the contrary.

Did you experience problems with engine overheating?

Like this?

https://scooterpartsco.com/021-vespa-c-801_802/thermostat-140-degrees-for-vespa-piaggio-aprilia-125300-p-36572.html