I'm going to guess that your bowl nut has some varnish in the jet. Have you looked in the throttle body to see if when you prime, the fuel actually pushes up out of the brass tube? You will see it rise about 1/8" or more. (Unless you're is an auto choke). Did you clean with carb cleaner in a spray can?

These carbs are pretty forgiving and generally are fixed by cleaning the jet or fixing the primer bulb.

@baymee, thanks for the quick response and my apologies as I forgot to state in my original post that this was an auto-choke with no prime bulb. Carb cleaner was used, I did have some build up in the brass nut last summer I'm the bottom of the float bowl. It seems as its a fuel delivery issue. The needle on the float moves freely and all jets are clear. I'm scratching my head over this one.

Not intending to be demeaning, but did you check for free flow of gas to the carburetor? Changed the fuel filter? Cleaned the vent hole in the gas cap?

@twelveguage, not demeaning, lol. The fuel flows freely from the tank to the carb. There are no "Guts" to this fuel cap, only a thin white plastic ring inside, I did check for seal and any obstructions through vent hole. I tore it apart again, thoroughly cleaned it again and for some reason the needle valve on the float stuck open, it would not seal and was leaking out of the filter, this all after I tried to start it and let it sit for about an hour to get my bearings and think about it more. After I saw it dripping, I went and pulled it and it started? I mowed the back yard and I am letting it sit to see if the float bowl will fill up and the needle leaks again...more to follow.

Thanks

PLambert

Clean ALL the holes in the "Brass Nut". That's your main jet!

A top down view of a main jet. Note the hole in the center. It's rare, but if you loosen the bowl nut and let the fuel flow, it should not stop flowing after the bowl empties, which would indicate a lack of flow from the tank. I use a 1/2 socket and small container to catch the fuel.

It now appears you have or had a leaking float seat.

{{gwi:126852}}

@bill_kapaun yes sir, I have done that with the carb cleaner. Flows through there with no issues. It is running again and the float seems to be "unstuck" for now. We'll see how it goes in a few days when I have to mow again. Up here in the Pacific Northwest I have to mow sometimes twice a week, in between rain cycles!

Thanks again for all the help from everyone.

Phil.

Some jets will have a tiny hole on the side that is easily missed. It'll look like a little black speck when clogged.
Not saying yours has one....

I fine wire like the wire tie on a loaf of bread tends to work decently.

@bill_kapaun yep, that is what I used, as well as a push pin. Mine looks just like the photo above with 2 holes on the sides, one solid hole from left to right. The main jet opening goes down into them and they are larger than the jet opening. I used te red straw that came with the Carb Cleaner and shot it from all three openings ensuring it flowed thru freely.

You guys have been great with the feedback, I really appreciate it.

Phil

You've got a Briggs Quantum 128T02 flat head engine fitted with a Walbro carb, Briggs p/n 796707. Good engine and carb.

Complete carb should cost about $30. Briggs also sells an overhaul kit 796612 for about $12.

Baymee and Kapaun instructions are good, but sometimes it's not possible to clean all of the internal passages, and either ultrasonic cleaning, or complete replacement may be required.

The automatic choke was not closing at rest can anyone help

See my previous message. I replaced the automatic choke, part was about $14, and the mower was good as new. I went ahead and paid $12 more for a carb rebuild kit. Since you're tearing it down, no better time than to redo it all!

I all ready did that and it didn't help.

Had similar sounding problem. Took off air filter unit and the flashing cover today, found the springs (throttle and choke ) snagged together. Got them separated, and jimmied free the auto choke arm behind the muffler. Gawd, it works a lot better now! Reading posts here really helped me! I did modify this mower a little, couple years ago- installed a fuel shutoff valve, just for my peace of mind.

The shutoff valve is a very good investment in the future !

Was still having some starting problems with my aforementioned mower. Today, I replaced the thermostat part of the auto choke assembly as well as the air vane spring. The air vane seemed ok, so I didn't replace that. Starts ok. We'll see in another week or so how well it runs.