Yamaha 70hp fuel problem

[Fishingfanatic]

Hi was wondering if anyone could help, i have a 70 BETO 6H3 L and it runs beautifully up to 10kph but anymore and it runs like a drunk dog. the first two plugs show a small amount of carbon as is expected the third is spotless like a new plug, it has spark in all three cylinders but after running the motor the bottom of the air cleaner is wet with fuel which makes me think blockage, i have checked the float, needle and seat and jets and can't find a blockage, any ideas please???

[99yam40]

have you checked your fuel pump for leakage?

[mitch]

fuel pump................ pull it off pump bulb see if fuel is leaking past diaphram straight into crankcase