Cooling
- Thermostat opens at 70–75°C.
- Coolant is about 0.9 litres, half and half.
- 60°C is a warm-up habit, not the thermostat.
RS125 · 1993–2006
Cooling
The thermostat is not the 60°C warm-up habit. That habit stays an MCN riding note. The opening temperature is a different number.
| Coolant | Half distilled water, half ethylene glycol antifreeze sold for aluminium engines. About 0.9 litres. |
|---|---|
| Thermostat begins to open | 70–75°C |
| Maximum valve lift | 3.3 mm at 90°C |
| Temperature sensor | 1 kΩ at 20°C. 50 Ω at 90–95°C. 15 Ω at 120–130°C. |
| Warm-up before hard use | 60°C. This is the MCN note already on the site, not the thermostat rating. |
| Water pump mounting bolt | 5 Nm |
| Radiator bracket bolt | 10 Nm |
| Coolant drain bolt | 10 Nm |
Oil-pump stroke and premix ratio are Not published in these pages. Two-stroke oil still goes in the oil tank. Gearbox oil is a separate fill, on thefluids page.
Notes from readers
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Sources
Research brief dated 24 October 2026. Where this page says “the brief”, that is the sourced master plan behind the first edition.