ok well the piston will be scored and rough with some black lines on the side of it if its damaged ,it should be smooth and clean on the sides if its ok it will be black on the top but thats normal carbon bulid up.the oil pump has a msmall bleed screw im sude just undo it for a minute and see if oil comes out of the screw hole,it does not need to be running.once it is running you can pull the pipe off the carb that comes from the oil pump for a short time and see if there is a small pulse of oil every 10 seconds or so coming out o it its really not alot so look closely.to be safe put a capfull of 2 stroke oil in the fuel tank and shake it about a bit before you pull the little 2 stroke pipe of to check its oil flow.whoever told you (leave the pump for an hour facing the floor to see if any oil dripped out) is wrong it will not come out unless its very worn as the oil has to pass the rubber veins of the pump and it cant unless the pump is spinning.
adam bike doctor
March 2010
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