I have a a 1987 150 ETXH , I cannot keep a idle or in gear at slow speed without cutting out /stalling , also very hard to start , engine performs normal at mid-high rpm and speed

I have recently replaced both fuel pumps, all 6 coil packs , rebuilt all 3 carbs, new ngk plugs, new batteries and cables, new fuel filter canister, and cleaned the on-board little one, the fuel in the tank is fresh and i tried a small portable tank with no change in performance , i use Yamaha ring free and fuel additive in there proper amounts. the problem/condition seemed to happen all at once and nothing i have done so far has made it any better .

adjusting the idle mixture screws seems to not have any affect either way , i set them per my factory manual , the choke does work and performs normally, i cannot get the motor started with using either / starting fluid ,

engine compression test is normal and even on all 6 cylinders , it seams simply to be starving/lacking fuel at idle or it is a electrical issue , the engine performs normally above 1200 rpm's in gear.

simply put i am at a loss as where to go from here , please offer any suggestions on what to do and where to look next for a problem.

thanks ...