navyman_98_99
07-07-2010, 03:05 AM
ok so i have a 78 glastron 23.5ft jet boat with a ford 460 that has been built like crazy and at high rpms like when the secondaries kick in it back fires thru the carb. the specs of the motor are... ford 460 +030, edelbrock 750, weiand stealth cj intake, speed pro forged dished pistons +22.00cc dove heads ported polished with 2.25 stainless and 1.76 stainless valves, comp cams bee hive springs, scorpion adjustable roller rockers, comp cams 7/16 guide plates and comp cams 7/16 pushrods. comp cams marine xtreme xm288h, stock crank, eagle h beam rods. high output oil pump, holley blue fuel pump and a truck oil pan. accell super coil and pertronix electronic ignition module. base timing is set to 6btdc as the cam spec card says. I always run 91 octain. Im wondering if I dont have enough carb. I do have the carb running pretty rich at idle but cant really tell when the secondaries kick in??? it has always done this since i got the motor from the engine builder so i just try to stay about 4500rpms and no pop thru the carb. also the boat has a brand new jet pump with a aggressor "A" impeller and shoulder wear ring because I thought the pump was slipping. when i give it some juice on the throttle it still does it it takes the rpm gauge to about 6500 and then backs down to about 6000 steady. it did that before and after the new berkeley pump. so i try to stay out of the throttle and just keep it steady at 4500 rpm untill i figure out the popping and studdering at higher then 4500 rpm or when the secondaries kick in. any help is appreciated. thanks in advance.