in my opinion , 5 Y# d+ ?6 v: O% R9 I7 k! \5 h/ L/ `1.the noise is coming from the gears .the engine oil lubricating the gear is not enough( P3 G, z2 |- e) L& V/ Z+ r
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2.the loadmatch of the Engine and the Pump is bad or the fuel filter has big resistance