Installing a carb on a 1991 3 HP johnson. Does the choke insert in the linkage round hole or the oblong hole?

Hi ,check the needle and seat in the carburator it may not be not be cutting off the fuel when the carb is full as this can cause flooding into the throat of carb

You need to take off the carborator clean take apart clean with carb cleaner and put it back together good to go make sure the fuel line has no hole

Under the lower carb, you'll find the linkage connector.
There is a screw, holding a lever on the shift lever ( coming from the SB side ).
Unscrew a few urns and you'll be able to slide the lever to free the vertical shift rod.
You'll gain better access with the removal of the air intake baffle and the lower carburettor.

look for wear marks in holes..usually one will be slightly out of round from wear.

U need a service manual unless you know someone who knows what is what. Nest time you will take a picture in advance before you disassemble something.

You may have left the fuel vent closed. If working, put a clear plastic fuel line between the fuel pump and the carb. Look for bubbles indicating an air leak between the tank and the carb.

On a rear occasion you can have some varnish flakes floating round the fuel bowl. But these tend to cause random problems than the "about 5 min" problems you are having.

It will have CV carbs, called constant velocity.
The cable and linkages open the butterflies on the intake side, the slides wont move until the air flow through the oval looking hole at the top causes the diaphrams to lift the slides.
you should be able to lift the slides individually with your finger , and they will drop down again.
I think the chokes lift a plunger in each carb, and is called an enrichening device, as it opens another jet to richen it for cold starts,the choke does not work the same way as a car ar a standard slide carb.

I am not having any luck with crossing the number you passed. I really need just the number off the engine air shroud just above the spark plug. Having said that. I understand you have a fixed speed automatic choke Briggs and Stratton engine without a primer bulb.

To gain access to the carb diaphram it is not that hard. The carb and gas tank are removable with just 2 bolts after the air-cleaner is removed. One bolt with spacer is near the gas filler opening and takes a 1/2 inch socket to remove. The other bolt is on the front bracket and is a 3/8 head. Once you have the bolts out, pull gently and carb will slide off of the intake tube.
Then tip the bottom of the carb toward you (STOP note the linkage position) and then remove the linkage.

Tank and carb off....

NOTE: The diaphram may stick to either the tank or the base of the carb so be careful when separating carb from the gas tank. Remove the 5 screws holding the carb to the tank and lift straight up making sure the diaphrm is not stuck.
The diaphram is under the carb and will have a spring on it if yours has an automatic choke. Note which side of the diaphram the spring is on. On the side of the carb there will be a rectangular plate with ONE 1/4" head on it. Remove the plate. This is where the choke attaches to the diaphram. Before removing the diaphram inspect it for holes in places where is not supposed to
have holes. If there are no holes visible on the bottom of the diaphram remove the diaphram by disonnecting the linkage inside the side plate. Again inspect the top of the diaphram for holes. If you find any tears or holes take the diaphram to your nearest lawnmower parts supply and get a replacement. They
usually cost around $6.00
If your carb has a single fuel adjustment screw turn it closed until it just starts to snug up counting exact number of turns from the original position.
Remove the fuel adjustment screw. If you loosen it until it is almost removed the whole assy will pull out with pliers while screw is still installed.
(O-ring type mating area) Clean the hole and reinstall the fuel adjustment jet.
Turn it closed until snug then adjust to original position.

NO HOLES in Diaphram or before installing NEW diaphram.
Check the fuel pick up tube for obstructions especially on the bottom screen.
You should be able to pass air though the tube orally. Noting the tube is free of obstructions install the diaphram by connecting the choke link on the side of the carb and install the side plate. Install the carb onto the gas tank and evenly tighten the mating screws. Then take the tank and carb assy to the engine and connect the carb linkage. Slide the carb onto the intake tube and make
sure the O-ring on the intake tube is inside the carb intake throat. Install the 2 mounting bolts for the tank and carb assy.

Test engine.
Install the air cleaner screw. Fill the gas tank all the way to the lip of the tank where the gas cap screws on. (This will ensure that the diaphram has gas in it) It should start within 2 or 3 pulls.
If it runs... your almost done.
AIR CLEANER
Take the air cleaner foam and wash it with gas until clean. Then oil the filter with oil gently squeezing it to make sure oil is evenly distributed.
Once oil is evenly distributed SQUEEZE out all excess oil by squeezing the foam as tightly as you can. Then install the foam and air cleaner.

Task complete.
Thanks for using FixYa

Kelly

Hi again Ed,
Starting at the carb throttle shaft, your linkage rod (with tiny spring wrapped around it) should be connected directly to the governor's arm. If there's more than one hole in the arm, connect the rod in the upper-most hole.
Now, at the base of the governor's arm is another hole (possibly on a tab jutting from the arm). The main governor spring should be hooked in this hole and then back to the sliding throttle control that moves when the lever on the dash is moved. (This one definitely has a tab and hole.)

The choke cable end hooks directly on the choke shaft and it has intuitive movement. Verify that the choke butterfly closes and opens relative to the cable control on the tractor's dash.

To insure that we only do this procedure ONCE, and we get it right the first time, let's set the internal governor to base-line at this time.

With everything bolted back up, move the throttle control lever on the tractor's dash to full throttle. Then get a 3/8 wrench and a slotted screwdriver and locate the round governor shaft coming out of the engine block. The governor arm attaches to this with a clamping-bolt. You will notice that the round shaft is slotted for a screwdriver as well.
Loosen the clamping bolt slightly with your 3/8 wrench, insert your screwdriver and rotate the round shaft clockwise until it stops. (It has VERY little travel, so turn it both ways to verify that your are at FULL clockwise position.)
Hold screwdriver there and move the governor's arm in the same (clockwise) direction until the carb's throttle is set to WIDE OPEN throttle. Still holding the screwdriver clockwise, retighten the clamping bolt with the wrench.
Next, move the throttle lever on the dash of the tractor to idle and back to full several times and observe the carb's throttle shaft, it should come down from full throttle to idle and back again freely.

Start the engine and be prepared to shut it off if it over-revs.
If it doesn't over-rev, your base-line settings are correct.

By bending the tab on the sliding throttle control (the one that has the main spring attached) you can now increase or decrease spring tension and change top speed of the engine. Do this in small increments and if you have a tachometer for single cylinder's set top speed to 3400-3600 RPM.

Sorry this is lengthy, but as mentioned above, we only want to do this once.

Hope this helps, and feel free to ask away if you need more info!
Dolf-