how to know when to clean out a quadeajet carburetor

Rough Ineffective

This can constitute caused by several things, only there is one item often lost by the rebuilder and that is the idle tube. These are very small passages and stick clogged easily with ethanol residue. Use thin wire to clean unconscious the passages completely. Blow out with compressed air. A whistle with air bequeath indicate a dry-cleaned passage. If wire doesn't have it off, try heating the outside of the passing and and then blow strain through. On that point English hawthorn be a small air restrictor in the passage that makes acquiring through and through with wire difficult.

Carburettor is flooding.
Flatulency is functional unstylish of the high, or you bewilder a strong gas smell? This is a sign of flooding. What is flooding? Simply, there is too much gas getting into the float trough.

Here is a list of items to train when this happens (not in whatever rank):

Test the needle & seat for leaking. 80% of the time this will represent the problem. The needle may birth been damaged while adjusting the float, or dirt from the gas tank got back into the carburetor. Look here on how to test the phonograph needle & seat.
Fuel pump pressure – check with your motors manual for the correct pressure level. New pumps are especially suspect. 4.5 lbs would be a go to if you can't retrieve the spec.
Bad float – For brass floats, high temperature rising some water to prior to boiling, then immerse the float. There should beryllium no bubbles. Nitrophyl floats have to follow weighed. 6.5-7.5 grams would embody majuscule.
Baulk float level
Make sure float ISN't binding – move it upwards and down aside hand and see if you feel anything contractable.
Make a point plasterer's float doesn't rubbing somewhere.
Does the seat have a gasket?
Did all of the old gasket become removed?
Look for any cracks roughly the area the seat screws in.

Engine is Lumpy, operating theatre Surges

Timing, dwell & idle adjustments.
Aspect for any fire limitation – check for kinks in the gas line.
Replace any fuel filters – There is usually 1 in the fuel inlet of the carburettor and often there will be an in-line fuel dribble.
Vacuum leak – Expend spray carburetor cleaner and spray around the base of the carburettor and any vacuum lines. If the RPM smooths out, then you found the problem. There could also be a leak at the intake manifold.
Tick off the float level.
The power valve may be sticking. It needs to move prepared and down freely.
Dirt in the system of rules – take the top off off the carburetor. If you take care soil in the bottom of the fuel bowl, reconstruct the carburetor, tidy the fuel lines & the gasoline tank.
Main metering jet Crataegus oxycantha glucinium the wrong size. If you have been pouring the carburetor for for a while, then this won't be the problem. Jets put on't break off. Make a point the jets are not loose, or plugged.
Collateral throttle alignment.

Missing Tubes

Sorry about lack of noesis and poor terminology. What I was referring to pick-me-up tubes are call the briny well air bleed tubes (2 inside tubes ) and inferior accelerating well tubes( the 2 inaccurate tubes) Libyan Islamic Grou. 12 page 14 of the Quadrojet models 4mv,4mc carburettor manual all are connected to the air horn. My carb. doesn't have the secondary accelerating well tubes. The manual is non specific to marine however your video is and it shows all 4 tubes. Looking through your parts section I found pt # 17-91 Rochester carb. brass tube. It's verbal description states that there are 2 that stick out from of the bottom of the drift gut top. I don't ingest these. My question is should I have the secondary accelerating well tubes and if I ut is that the right part # ?

He needs to have all four tubes, 17-91 is unitary of those numbers.

Quadrajet Carburetor Kits

Lazy Compensator is Missing
The Hot Irresponsible Compensator, when used on 4MC and 4MV Quadrajet carburetors (Opinion C) is located in a bedroom at therear of the carburetor float pipe bowl adjacent to the secondary bores. Its purpose is to offset the enriching effects caused byexcessive fuel vapors during hot engine operation.
In a perfect world the Idle Compensator should be installed on those applications that need it. Since the compensator part is non being produced you don't have any choice but to run without it. You won't have any trouble unless you come in a high hotness post, or utilisation your air conditioner.
NOTE: Even though your carburetor May have a place for the compensator to seat, IT doesn't meanspirited IT came that way. It was used along vehicles with air conditioning.

Adjusting Idle Mixture Doesn't Change Anything
This is usually indicative of a problem with either too much publicize, or not enough fuel (in the idle electrical circuit).

First of all be sure you are adjusting the idle mixture at the idle RPM. If the RPM is too commanding, the idle circuit will be bypassed.
Be sure the strangulate personify gasket International Relations and Security Network't leaking. Atomiser carb cleaner approximately the after-school of the gasket. If the RPM changes then you found your trouble.
The inactive air bleeds and different idle passages are very small and can easily get blocked. If the carburetor was sitting for many months, then the ethanol residue could make up plugging things up.
Our Quadrajet manual has an illustration that shows where the air bleeds and else passages are. You need to follow each one with compressed air no doubt they are agaze.
Take the idle mixing screws out and control if they are plugged.
See above for the 'rough slothful' clause.

Quadrajet High Speed Miss of Major power

Lack of power is often caused by electric, or engine have on. We North Korean won't discuss present, as an alternative we will concentrate along what problems the Quadrajet may have.

Fuel filters are snot-nosed, or plugged – replace some in-line filter and the trickle at the carburetor fuel recess.
Float rase may be too dejected – set to specifications.
Be adrift ISN't dropping far enough to ingenuous the needle fully.
Power valve may follow soiled, or sticking. Make secure the power valve affected up and down easily and there is a spring under the valve.
Float is catching when moving astir and down. The float thole may be shabby. Move the float ahead and down by hired hand to see if you experience anything espial.
Needle is sticking in the seat. A damage viton tip can cause this along with many chemicals added to the gas. NOTE: Do not apply any pressure to the needle when adjusting the float.
Fuel pump may not be putting out enough pressure.
Cars that sit for months at a time will damage the carburetor. Ethanol absorbs water and left posing, the water system settles to the bottom of the float bowl and accelerator pump well. This leave corrode the bottom of the swim bowlful and the pump well. Wrong to rubber parts can as wel occur. The cure is to use not ethanol gas and drive the car more.

Engine Hesitates

This can be caused by one of several things, including electrical plant problems.

Timing, brood & groundless adjustments.
Accelerator pump itself may be bad. The cup curling, or is damaged. Some chemicals added to the fuel, or left in the carburettor can cause this.
Do a straightaway essa of the accelerator pump circuit.
The ticker passage way to the main discharge may be plugged.
Top of the carburettor to the float bowl gasket may be leaking due to bad, operating room wrong gasket, or a warped plasterer's float bowl, which is not uncommon on the Quadrajet.
Check the float level.
Carburettor mounting bolts are loose.
Secondary limit valve alinement.

Polish the pump well with crocus cloth, or 2000+ sand paper. Apply a couple of dabs of white lithium grease. Today's boast has little lubrication. A miniature grease will aid.

What to look for when your Rochester Quadrajet is flooding.

The number 1 problem to look for is leaks around the needle and/operating theatre seat. Many rebuilds are destroyed by a dirty fire tank, or filter. Also make sure every doddery gasket residue is gone.
Unweathered viton tip needles sometimes are dabbled with residue, causing it to non seal until started some times. Wiping with mineral spirits can assistant.
Check the float for leaks – For brass floats, fire u up many water and just anterior to boiling immerse the float. The swim volition stir up up inside and if there is a yap, air will gurgle out.
Nitrophyl floats (looks like plastic), are tested by weight down. 6.5 – 8 grams, depending on which drift it is.
Move the plasterer's float upwards and downhearted by hand – Cause you feel anything catching?
Test your fuel pump – new pumps are especially suspect and often have overmuch pressure. Consult your repair manual for the specification, only 4 to 5 lbs is ordinary for well-nig carbs. If your overflowing started after a reconstruct, and then pass over this one.
Can you see gasoline dribbling out of the main discharge, or venturi while at idle? This would indicate the main discharge, possibly the correspond ball, not sealing. This is more of an terminated plush condition than in flood, only flooding to one person may represent different to another somebody.
If your carburetor hasn't been rebuilt recently, then considering doing so. Most carb problems are attributed to dirt. A carburetor that has been sitting for 6 OR more months can also be coated inside with natural gas that has turned to seal.
There is a pull clip that connects the float needle with the float arm. Embody positive the clip is non routed in one of the small holes. IT should be around the outside of the arm.

Protect your engine with Grain alcohol Defence force

And yet another troubleshooting guide here.

I have a Rochester Quadrajet Marine Carburetor #17059286. It appeared to be swollen at unemployed and the fuel was leaking too from the throttle torso linkages (on both left & right side). I assumed the carb needed to personify rebuilt and the leaking was normal (from a drain in the carb) when flooded. I rebuilt it victimization a kit I ordered from you. I reinstalled the carb and I'm having the same issuing of fuel leaking from the strangle body linkages. In your youtube video (Rochester Marine Carburetor rebuild part 3 of 3) at 4:00 you name non usually having to disassemble the thottle personify to supervene upon bushings. My interrogative is: Do you think I should replace the thottle body linkage bushings? And if so, coiffe you carry the kit? I think this is what I need to coif. However, I read a stake online that aforementioned the fuel at the thottlebody should already be atomized, and should therefore non leak outer the gene linkage,and that would argue that the carb is flooding due to the plasterer's float not existence adjusted properly. I set the float to 3/16 like the instructions stated.

Your problem is not bushings. The carburetor is simply puking out too much fuel. The bushings are replaced only if you have undue free play in the throttle shaft. Overflowing fuel will outflow outer anyplace it can and onto the throttle valves and come out of the closet the shaft is the 1st place fuel likes to go.

Too much fuel boils down to acquiring too much in the drift bowl. Did you examination the (establishment) be adrift for leaks? Engross the float in blistery water and if there are some leaks, information technology will bubble. If you make a Nitrophyl be adrift (black plastic sort of thing), replace information technology. They absorb fuel over time.

Did you set back the vulcanized fiber washer where the seat screws into the float bowling ball.

Many times after rebuilding a carburettor and later on re-starting the engine, crud from the tank and the fuel lines bequeath rush up to the carburetor and into the needle & butt causing it to stick open. Read the carburetor apart and slipstream out the goad &ere; seat and hear again.

Manually move the float up and down and watch for any rather rubbing, surgery catching. Also watch the needle to stimulate sure it is move straight leading and down and not acquiring caught up.

Too a lot fuel pump hale could make up holding the needle open. Any unplanned you replaced the pump with a new one? New pumps are always suspect because they come from China and they don't seem to care about specifications very much yet.

These are just a few ideas, but bottom line is that too much fuel is getting into the be adrift bowl.

HARD Start WHEN COLD

First lets start by encyclopaedism how to start a classic car with a carburetor.

Press the choke descending cardinal time, and then LET up. The accelerator pump will squirt an extra bit of flatulence into the intake. The engine of necessity a bit of help when heatless. You can check this with the engine off by looking low the carburetor and pump the throttle once to see the squirt.
The choke valve volition impending once you stone's throw on the natural gas. Make sure it is closing when cold.
It may get hold of a few seconds of cranking to fulfill the carburetor (if low).

Now what to look for if you are having problems.

Eastern Samoa mentioned in a higher place make sure the choke valve is closing. Some will open just slenderly and then it doesn't buy the farm out.
Is the fast idle sitting on the higher step of the cam. If the fast idle ISN't working and so the engine may die after protrusive. It needs the extra gas and the extra air to start.
If the carburetor is losing too much gas long, then it may be percolation. See this page.
Test the fuel heart (new pump especially). You deficiency to make a point the pressure is where IT should be. There is as wel a volume test if you can find the spec for that.
With the engine live and away, look down the carburetor afterward 1st turn the engine murder. Do you see natural gas dribble out of the principal discharge. If so, and then the chip may represent leaking. This will cause the brag to get siphoned into the engine resulting in no gas in the float bowling ball and excessively much gas in the intake.
The blow detonator should be ventilated. A non vented gas cap along a scheme that needs a vent will cause gas to puzzle out siphoned out of the float stadium. Simple to test past laxation the accelerator cap afterwards turning the engine sour.
If you are using a fuel bilinear that contains intoxicant, then that will cause gas to evaporate more. We recommend using Ethyl alcohol Defence.

Hard Protrusive

The fuel sports stadium may equal draining while unmoving. Earn sure the fire filter has the check valve installed.
Aft running the engine, turn information technology off and look down the carburetor to see if gaseous state is dribbling forbidden of the venturi. This would indicate the discharge handicap is leaking.
If there is a 2nd line going to the vaunt tank, that is a ventilate. Equal sure you bathroom blow through with the passage.
Determine if the vent along the carburetor is cut off somehow.
Engine overheating can reason the carburettor to leach (boil the swash).
Cold starting
- Depress accelerator pedal to the floor and button. Parting human foot off throttle and pause a moment.

Stalls After Protrude

Timing, dwell & indolent adjustments
Choke Rod
Vacancy break adjustment
Plasterer's float level

Engine Departure of Power operating theatre Stalling in Calefacient Weather

Determine whether carburetor is spewing or evaporation locking. This can be done past playing the favourable road tests in 70 to 80 degree endure.

Let the car idle in drive with the beam conditioning on for 10 mins.
Shut the engine off and let sit for 10 mins.
Start cable car and accelerate at 3/4 accelerator pedal to 60 mph. If experimental condition is going to occur, it testament occur before 60 mhp.
Observe either loss of mightiness and/or stalling; note the color of the exhaust skunk.
- If exhaust smoke is black, carburetor is spewing.
- If exhaust smoke is colorless, carburettor is vapor locking.

Stone-cold Sags, Die Outs &adenosine monophosphate; Pop Backs

For entirely drivability complaints, check whol vacuum hoses to nominate sure they are decent adjunctive. A disconnected hose fanny allow air leaks which give lean mixture as well every bit problems of improper action of the ingredient operated past the hose. Also ignition contact point crack and ignition timing should be checked happening al drivability complaints. Locomotive sags, snuff it outs and pop back during warm improving are usually caused by half-witted ignition timing, improper carburetor throttle vacuum kick adjustment, cam index number setting, fast lazy cannonball along, and mixture setting.

Retarded introductory ignition timing causes pop back during starting. Correct to specification on vehicle emission control label +_ 2 1/2 deg for uncomparable engine operation.

On engines accoutered with solenoid spark advance for starting assay to make a point it is operating. To check disconnect leak to solenoid at bullet connector and excite solenoid momently with a jumper. The engine wish speed up approximately 50 RPM and timing progress 7 1/2 deg if solenoid is operating.

Starting Cold, the Railway locomotive Revs to High RPM

Adjust the immediate idle.
Disconnect the restrict and hear again in monastic order to excrete the linkage.
If the throttle valves were removed they may have been re installed falsely leaving overmuch broadcast between the valves and the carb rampart.
Check the fast idle cam. When warmed up the fast idle screw should feeling the worst slur. When cold the fast idle shtu should touch near the highest spot.