New member in trouble already. I'm about to put a new injector pump on my 70 ish Massey Ferguson 165. Pretty sure the engine is a perkins AD4.203. Isn't the pump located by a dowel in the drive gear and if so won't the timing be correct if I just line up the scribe marks on the new pump the same place they were on the old one? I'm thinking 4 cycle 4 cylinder so they all fire in 2 revolutions of the crank . Doesn't the pump turn one revolution for the crankshafts 2 and fire all 4 in one revolution. Since it is located by a dowel pin in the drive gear it couldn't be installed out of time except by the amount it could move on the 3 mount bolts which the scribe mark on the case should take care of. Can someone straighten me out or tell me if I am thinking right. The reason I'm sweating this is she wears a front end loader that makes it impossible to turn the engine except by the starter or jacking it up and using the wheel. Any help appreciated much.