hi, i have a galaxy 21' with an '82 omc 305 5.0L engine. Last season boat ran fine except for backfire thru the 2bbl holley at or near full throttle so this season i replaced the 2bbl with a four barrel manifold(had it cleaned and beaded at machine shop) and a rochester quadrajet which i rebuilt myself according to directions and specs in manual. I also put new exhaust manifolds, risers and elbows since upon inspection the old ones were badly scaled and i installed a new coil from aaa marine, put in new plugs, cap and rotor; distributor has a pertronix electronic ignition module which upon inquiring with petronix; because i thought that could have been causing original backfire; they said to connect the red wire directly to the ignition switch because it needs 12volts and the resistor wire going to my coil doesn't allow that and could cause the backfire( since compression test turned out good). So i ran red wire to ignition switch. Well, started boat on trailer with muffs attached, set idle at 700 rpm and timed engine to 13deg BTDC as my manual says and boat idled and sounded nice. Put boat in water this past weekend and took it out for test run...idled fine and sounded great at 6mph harbor speed, then i accelerated slowly and it planed out, picked up speed and at @24mph it backfired thru carb slightly , i eased back on throttle it smoothed out and about 2 minutes later it just died as if key was turned off. Slight vapor was coming out of flame arrestor, so i waited about 2 min and cranked but it didn't start until i pumped the throttle about 5-6 times and kept it at full throttle when cranking. Then it started and i started to head back to port, again it ran fine at low speed but once at high speed it just died( big pull back felt on boat) , no backfire . Took same procedure to start again and i took it in at @6mph with no problem all the way took dock. Sorry for the long story, but i thought a thorough explanation could get me some ideas as to what could cause this before i start tinkering around. Have heard that it sounds like fuel starvation and should check fuel tank valve and fuel pump ( which went last season and i installed new one). I also have water seperator installed before engine fuel filter, i put new filters on before getting in water, and neither show signs of water....so if anyone can help i say thanks in advance....
