Coolant being displaced into reservoir.
I generally take care of these sort of issues easily myself but thought I'd ask the forum for their input and if anyone else has had similar on a Gen 4 before I go any further.
-Bike runs fine and does not overheat but coolant is being displaced into the overflow reservoir and not returning to the radiator resulting in significant air gap.
-There are no obvious signs of external coolant loss and the coolant is not being consumed (IE when returned to the radiator the final volume is the same)
-I inspected the radiator cap and it appeared to function properly but I replaced with new genuine anyway.
-All hoses appear fine on visual inspection and none collapse under vacuum or bulge under pressure.
-No blockages to hoses of radiator to reservoir, or reservoir to purge.
-Both coolant and oil appear uncontaminated.
My next thought was, shit; head gasket leaking compression into water jacket. I have tested with chemical test which indicated no exhaust in coolant. Test repeated 3 times same result. I am still sus on this as my culprit but the test suggests otherwise.
Next I guess I'll do a pressure test on cooling system but it seems unlikely it would draw air in but not push coolant out of any leak. Cylinder compression test after that.
Anyone got other ideas?
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