i just bought an 85 mercury blackmax oil injected 150. it ran bad. i cleaned the carbs and adjusted the floats. ran alot better. still idles a little rough and back fires or misses ever 30 to 45 seconds ,but not on que very intermittingly. it seems to run ok(a little rough but not that bad) on muffs but once in water it acts up. i put it in an 55 gal. tank at the house were i can work on it. i replaced spark plugs and wires they are firing hot.. checked compression ok. unhooked oil injection and premixed fuel. no change. noiced that the 2 lower carbs are leaking fuel. removed carbs and rechecked all work. still ok. pump the fuel up and i can hear it enter in the carbs until full then it stops and and primer gets hard. engine cranks up and dies(runs about a minute) check plugs there are wet. tried restarting and noiced fuel still leaking from bottom 2 carbs. there is an enrichment valve on the side. i unhooked it and cranked. engine will not start but carbs are not leaking...asked a dealer's tech. if this maybe the problem he claims there is a hole in my fuel pump diapham.. i checked the diapham and no hole. also noiced today no water coming out pee hole but there is exhaust coming out.. and there is no exhaust coming out prop until 2000 rpms..there was exhaust coming out prop at idle with muffs on..is it possible i have exhaust restrition..i was told adjust fuel to air ratio ,but can not find screw. can anyone help...thanks