Ok firstly if it's 50cc then it's Two stroke and has no real oil in the engine to speak of only what's injected by the oil pump so you won't see oil in the water or water in the oil if the head gasket had gone.can you see a water leak ? Is there water in the exhaust pipe ? If you run the bike does the water bottle bubble alot and pressurise? If so the the head gasket may be gone its only rubber and the head has 4 6mm nuts holding it on it takes about half hour to change it. You say you changed the waterpump? its not that easy on a 50cc and did you make.sure the drive belt was ok for it and also the oil pump as they use the same belt.if its 125cc or 180 then it's likely to be the radiator or the head gasket if you can't see the leak very easily.
adam bike doctor
January 2014
Hi,
A water leak from the head gasket of an engine will give several symptoms including:
1/ overheating
2/ white smoke from exhaust
3/ loss of coolant water
4/ imulsification of oil (goes creamy)
5/ loss of power
Leaks from outside the engine will cause overheating and water loss but won't affect the oil
westcountry
December 2013
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
