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My 5hp Briggs and Stratton Horizontal, diaphragm carburetor, mechanical governor, will only run on full choke. It's been out of service for 20 years, and I'm trying to revive it. I couldn't get it to run at all with the original carb even after a thorough cleaning. I just installed a new, in the box, Briggs and Stratton carburetor, part number 498298 (original carb is 492611). The gas is fresh, the oil is fresh and the gas tank was cleaned. The engine started on the first pull with the new carb, but will only run on full choke. As soon as the choke shutter breaks contact with the casting wall the engine stumbles and dies. The engine is model number 132232, type 2238-01, code 88042127. I would appreciate any help toward a solution.
Thanks,
Dave

On those models, in the top of the fuel tank, is the carb "bowl". And those over time can get rusted out, and develop
holes, even small ones, and not hold gas, or may hold gas for only a short while, and let the thing only run on choke, as the fuel leaking out leaks too fast to let it run on anything but choke.

I have repaired tanks in the past by removing all of the rust, and patching the cup with JB Weld, as a decent redneck repair.
Not sure about long term results.

Fish said:

On those models, in the top of the fuel tank, is the carb "bowl". And those over time can get rusted out, and develop
holes, even small ones, and not hold gas, or may hold gas for only a short while, and let the thing only run on choke, as the fuel leaking out leaks too fast to let it run on anything but choke.

I have repaired tanks in the past by removing all of the rust, and patching the cup with JB Weld, as a decent redneck repair.
Not sure about long term results.

Click to expand...

Thanks for the reply.
I'm pretty confident that the "carb bowel" is okay. When I took the old carb off the "bowl" was full to the overflow.

This engine is on a small portable generator. 20 years ago it replaced the original engine, and was used to run a circular saw on a job site for 1 day only before being stored under a bench in a wood shop. Except for the fact that it doesn't run properly, it is in like new condition.

Any other ideas on what might be wrong. I'm stumped.

Thanks again,
Dave

Start with some fuel down the plug hole.
If the engine is fine you should get 1 to 3 fires
Then try some down the carb throat.
If the valves are working it should run 15 sec to a minute the run out of fuel
If both of these work fine then your carb is just not as clean as you think it is.

Did you remove the gauze that covers the main jet housing then check you can see, blow or squirt through the main jet ?

You have a pulsa jet carb, which means the first thing I would check is, did you adjust the mixture screw on the carb to 1 1/4 turns out for initial adjustment? Once it is running you then adjust for best operation. Second, did you replace the carb to tank gasket? If you didn’t it may not be sealing, allowing air in, not allow the pump to operate properly. Third, I know you said you installed a new in the box carb, but it may have been sitting around for some time and the pump diaphragm may need to be replaced.

bertsmobile1 said:

Start with some fuel down the plug hole.
If the engine is fine you should get 1 to 3 fires
Then try some down the carb throat.
If the valves are working it should run 15 sec to a minute the run out of fuel
If both of these work fine then your carb is just not as clean as you think it is.

Did you remove the gauze that covers the main jet housing then check you can see, blow or squirt through the main jet ?

Click to expand...

Appreciate the reply!
You got me thinking. I reread my original post on this thread, and realized that I made a mistake. The engine wouldn't run at all BEFORE I cleaned the original carb. After I did my "thorough cleaning" it ran with the choke wide open, but it surged, or searched, or hunted badly. If I applied a little choke it smoothed out a little. More than a little choke killed it. If I held the throttle linkage steady when it was running with the choke wide open it ran fine, sounded good. Adjusting the idle mixture screw from shut to ready to fall out made no difference. I guess my cleaning wasn't as thorough as I thought it was.

Both the original carb and the new carb have a welch plug sealing the end of the main jet housing. The only place there could be gauze would be covering the screen on the end of the pick up tube on the new carb. I don't remember seeing anything removable there.

Any other suggestions would be appreciated.

Thanks,
Dave

Thanks for replying.
The new carb has no adjustment screw, the old carb has an idle mixture adjustment screw but adjusting it through about as wide a range as possible had no effect.
I did replace the tank to carb gasket with a new Briggs and Stratton part. The surfaces that the gasket seals were clean smooth bare metal.
I'll take a look at the diaphragm. Other than cracks or tears is the anything else I should look for?

Thanks again
Dave

Appreciate the reply!
You got me thinking. I reread my original post on this thread, and realized that I made a mistake. The engine wouldn't run at all BEFORE I cleaned the original carb. After I did my "thorough cleaning" it ran with the choke wide open, but it surged, or searched, or hunted badly. If I applied a little choke it smoothed out a little. More than a little choke killed it. If I held the throttle linkage steady when it was running with the choke wide open it ran fine, sounded good. Adjusting the idle mixture screw from shut to ready to fall out made no difference. I guess my cleaning wasn't as thorough as I thought it was.

Both the original carb and the new carb have a welch plug sealing the end of the main jet housing. The only place there could be gauze would be covering the screen on the end of the pick up tube on the new carb. I don't remember seeing anything removable there.

Any other suggestions would be appreciated.

Thanks,
Dave

Thanks for replying.
The new carb has no adjustment screw, the old carb has an idle mixture adjustment screw but adjusting it through about as wide a range as possible had no effect.
I did replace the tank to carb gasket with a new Briggs and Stratton part. The surfaces that the gasket seals were clean smooth bare metal.
I'll take a look at the diaphragm. Other than cracks or tears is the anything else I should look for?

Thanks again
Dave

Then the main jet is still blocked or the fuel level is too low in the bowl

bertsmobile1 said:

Then the main jet is still blocked or the fuel level is too low in the bowl

Click to expand...

I think I caused some confusion by talking about 2 different carbs, the original carb and a brand new Briggs and Stratton carb. The engine runs only on full choke only with the new carb. Could the main jet be blocked in a new carb?

I'll look into the low fuel level possibility. Maybe the diaphragm is bad or the pick up tube is too low.

Thanks for replying,
Dave

New member here and I know this is an old thread. I acquired an old 92 Briggs and stratton 5 Hp Industrial / commercial 132232-4036-02 attached to a pressure washer. It was in extremely bad shape. Probably should have been thrown away, but I figured I would try and bring it back to life. Im running into the same problem now after restoring it, the engine surges bad. If I apply about 1/2 choke it runs perfect. RPMs are steady at 3600. I also thought I did a thorough cleaning on the carb, removing both welsh plugs and really cleaning the fixed jet and all the orifices I could see. But no change. I even tried a different cheap carb. Similar problem with surging but if Choke is applied the engine stalls out. I’ve taken the carb out again to clean it.. now waiting on all the seals to come in. I figured it is an air leak somewhere but trying to find it Has not been easy. I don’t have a service manual, but found somethings online . what is the normal compression on a 5 hp? I have 75#. it starts first pull, i just don’t know what the “range” should be.

After cleaning are you sure you set the float level properly? Sorry wrong carb, disregard. Did you replace the fuel pump diaphragm?

I did replace the fuel pump diaphragm, spring and cover that sits on top of the spring so it does puncture the diaphragm. I did order another diaphragm since I took everything back apart. If I can figure out how to post pictures I will upload what it looked like before hand and after.

Well forgive as this is the first time trying to posts photos. But I added Some pictures of what it looked like before, what the carb looks like now and the overall end result.

Did you check the tank for rust? Biggest problem with this engine is rust in the tank and fuel cup getting sucked into the carb. I have seen a new carb plug up the main jet in about 15 seconds from rust in the fuel cup.

Thank you for the info. The original fuel take was completely rusted through. I actually found a good used one to replace it and put the red coat lining in it to help protect it. I’m afraid because of how rusted the original tank was, that it really messed up the fixed jet in the original carb. That’s why I tried a cheap one with no success. Now I have pulled the welsh plugs and cleaned everything and used my ultrasonic cleaner on the original one. This is about the third time doing it. I do have all the seals and plugs on order. I figured I would try it one more time. Just did not know if I was overlooking something easy.

Check your fuel line for cracks as well. Spray carb cleaner around the carb to ensure it is sealed. My fuel line had an almost invisible crack allowing enough air in for surging, but did not leak. So check the whole fuel feed system for air intrusion.

joe_cooler said:

Check your fuel line for cracks as well. Spray carb cleaner around the carb to ensure it is sealed. My fuel line had an almost invisible crack allowing enough air in for surging, but did not leak. So check the whole fuel feed system for air intrusion.

Click to expand...

There are no fuel lines

Thanks for the idea Joe. I didn’t think about that. I’m guessing you are talking about the fuel pickup tube that has the plastic filter piece on? I know I sprayed carb cleaner through it and didn’t notice anything out of the ordinary. But I will look closer tonight.

joe_cooler said:

Check your fuel line for cracks as well. Spray carb cleaner around the carb to ensure it is sealed. My fuel line had an almost invisible crack allowing enough air in for surging, but did not leak. So check the whole fuel feed system for air intrusion.

Click to expand...

Joe,
I understand you are elated that your problem has been resolved , but every problem is not a nail for your hammer to hit.
This mower has an internal fuel pump directly into a cup which acts as a float bowl so is fully internal .

So, I am not the best with carburetors and I am learning as I go. I had a few moments to look at things and was hoping someone might educate me on what I guess is the idle circuit? So I looked at the fuel pickup tube and the tube looks fine with no cracks. I am replacing the plastic piece that attaches to the fixed pressed in tube. But what I’m curious about is how the adjustment screw I have for idle operates. I attached some photos and put some arrows pointing to the particular hole I’m talking about. now, it may just be my eyes but when I remove the idle adjustment screw and look down at the base of the hole it looks like there is two small passages. One of the passages goes up to the welsh plug that I removed and you can see I put a small wire in it in one of my photos. Well on the opposite side it looks like there is a hole but nothing will go in. there Is a ball plug on the underside right where that hole is. i am guessing that is normal but I just don’t understand how the adjustment works if that hole doesn’t physically go anywhere. What am I adjusting, airflow Only and no fuel? I’m sorry for the stupid questions. Trying to learn as well as get this motor operating properly.

Yeah, that was a bit rough..

That will buff out.

Lol yeah it was in bad shape. I’ve replaced the tank. I just don’t know what might Of happened to the fixed jet with all the rust.

So I figured I would update everyone. Got the original carb working. No surging now. Ended up being the idle circuit. One of the small passages was blocked. Ended up having to remove one of the ball plugs to really clean it. The only thing I find tedious is setting the rpm. For the post part I have the max rpms set to is 3600. Occasionally it dips to 3540 or goes up to 3660. The idle was trick. From what I read it’s supposed to be set to 1750. I like the sound better when it’s in the upper 1800s or lower 1900s. 1860 to 1920.