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quadrajet-4bbl

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redsnapper386

Regular Contributor
guy,s would a quad-4 flood out,and quit after idleing for 30 min. to 1-hr.i have 2 rebuilt quads that are doing this .they have been sitting for a good year. i installed a new carter mech. fuel pump with 6 psi.the carbs were stored dry with no fuel in them.fuel leaks out at throttle shaft,at the base of intake,and flows inside the primarys.of course my carb shop said to bring it back for another rebuild.if this is a nightmare with quads,then can someone give advice on a more dependable carb.i hear a lot of good stuff about the idlebrock 600 cfm.at this point i am ready to try anything.i cannot figure this one out.i have allway's used quads in my cars, and boats.thank's in advance.
 
Give this a read.

http://www.thecarburetorshop.com/Troubleshooting.htm

In my opinion there other options to prevent the symptom you describe.

Being it's so slow here nowadays and the original poster will bear with me lets leave this thread go on and have others give there opinion, besides switching carbs.

Is this a emergency ? Your going to use the boat lets say within the next few day's ?

You do not need different carbs and the expense.

You are positive the fuel pump is giving 6 psi ?
 
no emergency, yes 6psi. i forgot to mention that the idle does not stay set at 650-700.every time i shut off motor i have to turn in screw a little on restart,then after a few min i have to back it back out.this is on both carbs.the elec chokes are not in use because here in fl. it is warm year round. all bolts are torqued,new gaskets,no vacume leaks.thanks
 
You didn't mention that little tidbit of info. Don't worry everyone leaves something out. Then they remember latter.

Your idle circuit is clogged a little also. Only gonna get worse till cleaned.

A complete rebuild maybe not needed. You comfortable to break it down and clean it yourself it's actually easy.

A can of berrymans or when i don't have it i soak for hours in gas the parts.

Break the carb down with no gaskets or o-rings no rubber soaks understand.

Then in a coffee can or old pot big enough to fit all the parts pour gas till it covers them and let sit maybe over night. Don't forget the accel pump don't soak, and if there is a ball bearing under it that has to come out. Soak it.

Then fish out the parts or pour gas out and blow dry all the parts.

With a can carb cleaner, shoot all the holes with the straw and blow dry again.

Make sure you got the jets screwed out and the adjustment screws completely out of the carb body and gentle with the o-rings, they don't soak the rubber remember.

Everything nice and dry and clean build the carb again.

The adjustment screws very gently all the way in do not bend the tips. Out 2 turns to start then on the water the final adjustment.

Before you do all that want to try to shoot some carb cleaner in with someone else driving the boat till it almost conks out, then stop shooting let the motor recover, then shoot some more. Around 3 thousand rpm will do. But on the water don't rev that high on the trailer with a garden hose no good will collapse the hose capiche ? Half can will do if that don't fix it the cleaning will have to be performed.

Post back others here will help also.
 
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thanks chief,will get started soon.will get my carb shop buddy involved.i have 6psi,and no hurry for now. i still wonder if there is a better carb to go with.i keep fuel treatment in tank,run the motor year round,change filters etc.i go offshore alot,and luckily this trouble has happened in my driveway.can any one give input on the edelbrock 600.thanks.
 
The marine rochester is a superior carb!!! No better for a stock marine engine.

A spread bore carb (small primary and large secondary) type carbs are best for this use.

If you are running a performance motor then there are many choices that are easier tuned.

The only reason merc went to a webber 4bbl was the rochester stop bieng manufactured.

The rochester is completely rebiuldable including throttle shaft bushings......
 
There are many reasons why you may be experienceing your issues. If I am not mistaken you said two rebiulds doing the same thing, Correct? Who rebiult them? You? If you or someone else who may have done both then your answer may be in the commonality of who did the work.

If you have a carb friend let him check them out and let us know what he finds......
 
thanks to all.my problem is the idle circuits,my carb shop will fix.i bought 1 of the carbs on e-bay,and the other was remaned at a local carb shop that is top notch,they build carbs for off shore racers.this is part my fault for using ethanol fuel at the local gas station.no more,from here out i will use marina 89 non ethanol.also, useing startron more often will be a +.thanks again.
 
One thing about Rochester Quads is that early versions leaked fuel from the float bowl into the intake manifold while sitting. This was caused by the welch plug staked under the two main jets on the bottom of the float bowl. A work around was to separate the throttle plate and float bowl and epoxy the two holes where the plugs were staked in.
Bert
 
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