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Discussion Starter #1
I have an Ariens 924050 s/n 006302. Engine is HM80-155128E s/n 9017 D

Tecumseh Owner's Manual and Operating Instructions is 181-151-1 dated 11-1-78.

(I posted a while ago about the crankcase breather leaking gas. A partial carburetor rebuild solved that.)

During the 2018-2019 season I needed to run it at full choke to keep it running.

I could not get it to start before the 2019-2020 season.

From perusing forums here I tried to contact Pat's Small Engine Plus. But I couldn't get past the spam filter.

I ran out of time so it sat out last winter while I used a backup. Fortunately I only used the backup 7 times for around 9 hours total.

This is the second time the carburetor has acted up. I think it is time to replace it instead of trying to rebuild it again.

Original carburetor was replaced about 12 years ago after two rebuilds (one by me, one by a repair shop) did not fix a drip from the air intake. So the current carburetor is not original.

Which complicates things. I have been to PSEP but they list multiple HM80 replacement carburetors. I don't know which one to choose. As I can't find the current carburetor anywhere, 5002E7K.

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It appears from looking at various parts diagrams the original number was 632037. Now superseded by 631957B? But I don't know what the original carburetor number was, so I can't be sure.

Help me, [Snowblower Forum] Obi-Wan Kenobis. You're my only hope.
 

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HM80, HM90, HM100, they all use the same carburetor. Just order one on Ebay, or Amazon and be done with it. Choose the one that is 4.5 stars and popular. Search for "HM80 carburetor" and order one. They all the same, just made by different people.

It is a dinosaur engine and people still looking for OEM parts. Everything is Chinese now a day. All carburetors go bad in a year, or two years if you don't drain gasoline out.

I have the same engine using Chinese carb on Amazon. It looks exactly the same and work well.
You have two options: adjustable or non-adjustable. Either one works fine. I went with the non-adjustable carb, because I did not want to mess around with it. I want to play around with it now.
 

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Discussion Starter #4
Got tied up with other things...

After wearing out the Oracle of Google with my consulting, finally figured out the carburetor number here and on page 27 of the Tecumseh Carburetor Identification, Troubleshooting, and Service Guide PDF (Tecumseh Power/Service Dealer's and Technician's Training and Informational Series/Carburetor Identification, Troubleshooting and Service).

The first four letters are the Manufacturing Number, where 5002 maps to Service Number 640349.

The next three letters (the cause of my confusion) are the date code.

First letter is the month, E being May.

Second letter is the year. As the original carburetor was replaced around 12 years ago, I have to assume 7 is 2007.

Last letter is work day of the month, so there are enough letters. Which would mean K is Monday of the third work week.

(In case anyone is wondering)

So now I have something concrete on which to search. (All those carburetors out there is what sunk me last year. Not being a small engine person, could not sort them out in time.)

As it is a 40+ year old engine, I don't think I can take a chance on a non-adjustable carburetor.

(FYI dman2, the first link you posted is now dead. I assume that was for an adjustable version?)

As I made preliminary searches on 640349 I saw comments about needing to tap the holes for the intake. Fortunately nuts and bolts are used here, so that shouldn't be an issue. Just need to verify the bolt hole spacing, bolt hole diameter and intake/carburetor hole diameter matches.

But the throttle mechanism is bolted to the carburetor side using those two holes. I don't know if that will be an issue. I suppose I can use self tapping screws. If that is what others do. (I do not have a tap and die set.)

So based on the advice here, I search on 640349 for adjustable versions. Start with the 4.5 and up ratings. Then look at the pictures for a match (e.g. governor and choke linkages). Then look at the questions and comments for problems and ideally use on an HM80. The actual carburetor and vendor won't matter in the end if everything else checks out.

Sound like a plan?
 

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Sound like you have thought it though. Just look over the listing photos to be sure the linkage attachments are the same and go for it.
 

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I definitely recommend the adjustable carbs. The non adjustable ones may work, may not... and you can't fine tune it. I just had one delivered today, cost 10.85 shipped on amazon. My general rule is if I give it a quick clean, and then soak it in the ultrasonic cleaner and it still doesn't work its not worth my time for 10-15 bucks to replace it.
 

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Discussion Starter #7
I did my first perusal of dozens and dozens and dozens of carburetors.

I noticed not a single picture had the carburetor linkage as shown in the first and third pictures above.

I can remove the linkage after removing the plate, so it's not bolted down.

I have zero experience with Chinese carburetors. Can I just swap linkages?

That is:
  1. The linkage is removable on the Chinese carburetor (after removing the plate).
  2. The diameter of the "rod/shaft" hole is the same so the Tecumseh linkage will just slide in and freely rotate.
  3. The "rod/shaft" hole length/depth is the same or more so the Tecumseh linkage will sit snugly on top of the carburetor.
  4. The Tecumseh plate can be reused (fits in the throat) or the Chinese plate can be used on the Tecumseh linkage.
I will probably resume my search using HM80-155128E first. Then see if any resulting "hits" are adjustable 640349. To have a better chance of fitting the intake, etc.
 

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A replacement carb almost always does not include the linkages, so the Chinese one should be a direct fit after connect the linkage rods and springs. Oh, shoot a few photos first, just in case you do not have a photographic memory. I used to, but ran out of film decades ago.
 

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The choke lever on your current carb is a little different than others I have seen on amazon. You might have to modify the choke linkage if you go with a carb with a different choke lever design.
 

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Discussion Starter #11
Here is another picture showing the choke linkage is controlled by pushing/pulling on a wire, finger loop at the end. No sliding lever or rotating knob.

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It will be tricky to modify that. Especially as the "slot" length for the wire seems to be shorter on the Chinese carburetors. It is about 7/8 inch long on the Tecumseh.

Which is why I asked if I can just swap the choke linkages between carburetors. If the four conditions I mentioned pan out.
 

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Discussion Starter #12
I searched and searched...

Came across this carburetor on Amazon.

Carbhub 640052 Carburetor for Tecumseh 640349 640054 640058 640058A HMSK80 HMSK85 HMSK90 HMSK100 HSMK110 LH318A LH358SA 8HP 9HP 10HP Snowblower Generator Chipper Shredder - Tecumseh 640052 640054 Carb

640349 was listed, so far so good.

In case the link goes poof! like one of the links in an above post, searching on B079NTGG2K should list the above link (this carburetor).

Perusing the comments came across one who mentioned transferring the choke assembly. Yeah! An actual useful comment.

Ordered one, got it in 9 days. Enclosed in bubble wrap in a small white box. Label with X001P2Z1S9 plus Carbhub Carburetor f ... hipper Shredder Carb .

Came with a gasket. I will probably trace out copies on the gasket sheet roll I have. Might as well make use of it.

Confirmed that the choke assemblies can be swapped!

But first some comparison pictures as this was the first ever ChiCarb I have ordered. Obviously the cleaner carburetor is the new one (on the left). Choke end first...

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Reused the old choke plate as new and old are the same.

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Interestingly, I can't close the choke all the way as one can see on the right. But it was the same with the Tecumseh. I have to wonder, did the Tecumseh come with the rotating knob choke mechanism? And the shop swapped the assemblies with the original carburetor way back when? I don't remember anymore if I could close the choke completely on the original carburetor. But there never was an issue with starting. Only had the choke closed as-is for a few seconds after starting.

Without the chokes, noticed the "feeds" are different, new on left again:

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Hopefully that won't be an issue.

Now the intakes (if that is the correct term):

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They are pretty much the same size as they match when mated:

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The bolt holes on the right side are not tapped as is mentioned frequently. But I didn't have a problem carefully starting the bolts as can be seen on the right. And the bolts aren't even self tapping:

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Top view. The throttle linkages are similar enough, the hole to use is pretty much in the same position (bottom right corner).

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The bowls are different. It appears the new one is adjustable and the old one wasn't.

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That could be a help if I need to adjust things. Fortunately there are a lot of videos out there on carburetor adjustment procedures if any are needed. And I can use all the help I can get!

I didn't include a picture here of the other adjustment screw as there is one on Amazon showing the adjustment screw on the side between the bolt holes.

So, get the carb installed. Then do the other maintenance as it sat on the PUP list last season. The gear on the starter that engages the flywheel has worn down, got replacements. Will have to see how hard that is. Check the oil. My Dad started using Mobil 1 decades ago and I have continued. I am pretty sure the last time I changed it was when that crankcase breather problem contaminated things.

When I have used the snowblower, I shut off the gas and let the engine stall when I was done. Does that suck the bowl dry? I never used the bowl drain at the end of the season. I wonder if there was left over gas that contributed to the current problems. I only use non-oxy premium. Fortunately that is much more prevalent around here now.

Should I use some of the blue (non-heat) lock tight type product on the choke plate screw?

I went through all this detail to help anyone else with an old Ariens in the same situation. There are so many carburetors out there.

I will update this with my success or failure.
 

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Edit - If you install either carb, yes to blue locktite on the screws, if they ever come loose they are liable to be "inhaled." The Tecumseh service handbook says to buy new ones (theirs) with a dry thread lock substance.

A friend gave me a 924040 last month and it was stored with a tank full of gas. All that was left after 10 years was tar in the bowl and carb body, so you are starting off from a better place. I tested the machine with a $12 amazon carb after cleaning the gas tank and replacing fuel lines, but it wasn't the best. The mixture adjustments both seemed to lack precision, and the throttle mounting holes were threaded, but not deep enough. I considered transferring the unique throttle shaft (same as yours with the wire loop actuator) over to the Chinese carb, but decided that was a last resort.

I thoroughly cleaned the old carb & used key parts from an ebay rebuild kit - the O-rings, needle & seat & the welch plugs. I cleaned & reused most of the original small pieces after a bath in citric acid. Tonight the machine started on the first pull with both screws backed out two turns. It idled well at a low speed and full throttle was easy to dial in, and sounded "right". No popping or hunting.

I don't have a carb dip tank or parts washer, I use TSP from the Home Depot paint department and boiling water to dissolve tar & grease - two baths, rinse well and blow out the passages with air. Drill a small hole and thread in a screw to pull out the welch plugs, then you can push a wire through the 3 idle ports. It doesn't take a long time to clean everything and I feel like it's a superior product when it's done, and I've used Chinese carbs before, they have a place.

I'd encourage you to give it a shot, you might be surprised how simple and reliable these carbs are.
 
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