I have an Ariens  Pro-32 (926039), 420cc B&S, #25M137-0110-F1
This is my first post, let me know if the B&S section would be a better place to post.
 
I'm working 300 miles from home to get the Ariens running for my daughter.  I don't need it at my new home in NC.
The tank was rusted, the the carburetor gummed up after sitting for a few years.
 
I restored the gas tank, and it is good, with a new fuel filter.  I dismantled the carburetor and cleaned it very good.  I do not have a rebuild kit at this time.
 
After the cleaning, it now starts and runs, but only when the choke is on fully closed.  As soon as I open the choke even one notch on the choke knob, the engine dies. 
 
Has anyone rebuilt the carburetor on the 420cc engine before?  I'm at a loss on hoe the choke adjustment knob is removed.  It is plastic, and I don't want to break it.  I can't fully remove the carburetor without removing the choke knob.
 
My guess for the running problem is the jets and metering needle need a better cleaning that what I can provide with the carburetor on the engine.
 
Also, if I get a rebuild kit for the carburetor, I'll need to know the engine date code.  Where is that???
 
thanks.
 
 
 
 
 

Been there, done that with allowing a carb to gum up.  I will surrender and just order a new carb and replace it.  Just remember to run the tank out of gas to allow it to sit during the winter.
 
You'll never get that carb back into original working order.  Had the same thing happen to my roto tiller.  Turned it in for a tune up and the local repair shop replaced the carb after trying to rescue it.  They are not too expensive.
 
Good luck!

Ok, the choke knob lever should pull straight up, usually in the FULL CHOKE position..
 
https://jackssmallengines.com/jacks-parts-lookup/manufacturer/briggs-stratton/briggs-stratton-engine/200000-399999-series/25m100-to-25m199/25m137-0110-f1
 
The carb rebuild kit is about $55, a new OEM carb $100.00
 
The bowl has to come off, the main jet (not shown in the parts diagram for some reason) has to come out and is very likely clogged... There's a nozzle up behind that, that sticks up into the venturi. 
 
Gently push that out from the venturi.  That has EXTREMLY SMALL HOLES that clog easily.
 
If you don't have a jet cleaning tool, cut a single wire off a wire brush and clamp with a small vise grip.
That'll JUST fit in the cross holes of the nozzle and plenty large enough for the main jet.  
 
BRAKE cleaner works best for not damaging rubber parts.
It's rare I have to rebuild a carb, (float style) when it's just clogged. 
 
Get those jets clear and you should be good to go..  
 
Picture is that of a similar carb ("General" generator-Chinese engine) I cleaned...

 
 

Ok, the choke knob lever should pull straight up, usually in the FULL CHOKE position..
 
https://jackssmallengines.com/jacks-parts-lookup/manufacturer/briggs-stratton/briggs-stratton-engine/200000-399999-series/25m100-to-25m199/25m137-0110-f1
 
The carb rebuild kit is about $55, a new OEM carb $100.00
 
The bowl has to come off, the main jet (not shown in the parts diagram for some reason) has to come out and is very likely clogged... There's a nozzle up behind that, that sticks up into the venturi. 
 
Gently push that out from the venturi.  That has EXTREMLY SMALL HOLES that clog easily.
 
If you don't have a jet cleaning tool, cut a single wire off a wire brush and clamp with a small vise grip.
That'll JUST fit in the cross holes of the nozzle and plenty large enough for the main jet.  
 
BRAKE cleaner works best for not damaging rubber parts.
It's rare I have to rebuild a carb, (float style) when it's just clogged. 
 
Get those jets clear and you should be good to go..  
 
.
 
 

Thanks for the reply and info.  The kit part number has changed, (new # is 84004389), and I've been on the B&S web site trying to get the carb kit ordered.  The part selection indicates it is "not available".  I had the same response a few weeks ago when working with the fuel filter for the gas tank.  I was able to reach customer service, and they said the part was out of stock, and would be available in August.
 
I've tried to reach customer service today, but can't.  I've tried two different phone numbers, but only get info to find a dealer.  Not sure if their phone menus have change or what, but I can't reach a real person now.
 
I'll be returning to my daughters home  in 2 weeks.  I was hoping to have the rebuild kit in hand to finish the work on the snowblower.  Previously, I have had the fuel bowl off and cleaned it like new.  I used spray to clean the carb with Q-tips, etc, but wasn't able to get the carb removed.  I'll try the get the carb removed when I return, now that I know the choke lever should just pull straight out.

Does the carb just have a regular, (round) o-ring between the bowl and carb body?
 
If so (I believe it is), you really don't need a re-build kit.  If it's a NIKKI carb, (very weird base o-ring)
that gasket you would need.
 
Simply pull it apart, main jet, emulsion tube should un-screw out (they'll be a slot), or simply pish OUT.  A screwdriver down the venturi with some pressure will pop it out.
 
There's some EXTREMLY SMALL HOLES in there that must be cleaned.  A re-build kit will NOT COME with that nor the main jet...
 
IME, your wasting your time hunting down a kit.  The carb just needs a good cleaning.  
 
If you still can't get it to run, a new OEM carb is roughly $100.00. 
A shop will charge you $75 to tell you its broke, sooo...
 
.

https://jackssmallengines.com/jacks-parts-lookup/part/briggs-stratton/84005069 
 
https://www.ereplacementparts.com/carburetor-p-1728955.html 
 
 
 

I've tried multiple vendors to get a rebuild kit.  It just isn't available until early fall.  I may try another tare-down and cleaning.
 

I had a similar problem with my Deluxe 24 Ariens snowblower with AX 254 engine.  After several days of "take apart/ reverse order" I went to my local Ariens dealer and ordered the following:  Full shutoff valve, fuel line, governor spring, and OEM carb.  The cost?  $140.  As stated in a previous post...cleaning and/or rebuilding the OEM carb did not work for me.  I had to run half choke and the motor still ran very rough with exhaust smoke.  I am replacing everything fuel related for a very reasonable cost in my opinion.  The machine is 8 years old and although I run it dry every year there seems to me, to be no way around these carb problems.  I also adjusted the valves, which were a little tight.  I expect this thing to run fine when I get it back together.  I will let you know.