Coolant for YAMAHA two-strokes (YZ 85, 125 and 250, DT, WR): biodegradable TWIN AIR in a 2.2 litre can, and LIQUI MOLY concentrate in 1 litre.
A motocross two-stroke heats up fast when it is stuck in a rut or crawling along an enduro trail, so the coolant must stay clean and topped up. If the level drops with no visible leak, look at the gearbox oil: if it is milky, the water pump seal is leaking; if not, check the cylinder head O-rings. Never open the radiator cap on a hot engine.
To drain, open the screw on the water pump cover with the engine cold, flush with demineralised water if the coolant is dirty, refill slowly to push out the air, and top up again after a first warm-up.
For the YAMAHA two-stroke cooling system: radiators, radiator caps, hoses, water pump repair kits and top end gasket kits; the whole range is under YAMAHA two-stroke cooling.
