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Flooding problem in quadrajet spreadbore

APorter

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Hi all. Thanks for looking.
I have a flooding problem in my 1981 Viking deckboat. It carries a 305ci motor with a quadrajet spreadbore carb. I bought the boat this summer with the understanding that it sat for 2 yrs so I immediately took the carb off and did a good cleaning and bench rebuild. The reputable gentleman I bought it from was very adamant about how good the engine ran.

The rebuild kit came with all the gaskets, float needle, check ball and screw, filter and gasket and all the springs.

Upon installation, the engine will start right up with a moderately high idle but after a few seconds it will stall out and will not restart for an hour or so. The carb seems like its flooded and the plugs will be very wet with fuel. At present, the plugs are fairly clean with a small amount of black carbon build-up. I'm not sure how to adjust the air/idle screws, especially if I can't keep it running long enuf to get in there.

Side note: I replaced the mechanical fuel pump with a remote electronic pump that pushes 5psi continuous as well as all the fuel lines with new 5/16 hose.

Any adjusting tips or insight is greatly appreciated. Thx!
 
for starters....screw the idle screws in lightly until they seat, then back out two complete turns. also look for any vacuum leaks. especially at the back of the carb. as for the flooding issue....that can only be caused by the float level being incorrectly adjusted,(and the float drop), or the needle seat has something in it, or the electric pump is over powering the needle seat. at idle the pressure may be fine,,,,,,but as you rev the engine, the voltage increase in the charging system may cause the electric pump to give you a higher pressure. but...if it stays at five psi. that is fine. one thing that people overlook on these carbs,,,,is that the floats can become "heavy", saturated with gas, or have a piercing.
 
2X on replacing the FLOAT...especially if it is original...and it was sitting a few years.

make sure you check the needle and seat to make sure they seal before you reinstall the carb.

Unless you got a custom made kit, the baseplate gaskets in most are not real good and shouldn't be used...a potential source of vacuum leaks but that won't induce flooding
 
Thanks for the advice. Turns out the coil was bad. It would start on the primary charge but would die when it turned over to secondary. That explains the plugs being wet and not able to restart for an hour. I've had the boat out twice since the coil was replaced with flawless results. Running a little cold so the water system is the next project. Thanks again.
 
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