Sorry if some of this doesnt all make sense. New to the bike world. had a top end rebuild on my TDR 125 a couple of weeks ago. After this it began to leak water. Got the barrel and head skimmmed and put in a new gasket set. Bike ran perfectly for about 250 miles after this but yesterday it started to over-heat really quickly. Checked coolant level seems perfect, not airlocked and isnt leaking water from anywhere. Noticed a black oily residue on the bracket near the chain. I cleaned this off to see if it was a fresh leak but after driving there doesnt appear to be any more leak. Pipes around the radiator are hot which i think means that the water is circulating!?

Any help or suggestions greatly appreciated

Cheers

Sticking thermostat? Siezed or broken water pump? How do you know it's overheating?

Sticking thermostat? Siezed or broken water pump? How do you know it's overheating?

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It has a tempature gauge. thermostat wasnt opening, took it out and problem solved. Need to get a new one now.

Thanks for the suggestion