Help, please: Club Cadet CC 98 M mower, can't figure out the choke

I need to sell this mower, but I have to sort out the weird auto-choke. I'm sure it's missing some parts, but no idea what since I haven't had it from new. At present, the choke will stay closed from spring pressure, and once it's started, it will open and close every few seconds, resulting in an RPM surge as it cycles. After it warms up, it will stay open and run okay.

The autochoke has to have some sort of actuator. The ones I'm familiar with use a thermostatic coil spring (like I had on my slant six engines), but this one is very different than the typical Briggs and Stratton, and I can't find a schematic for the part on this thing.

The carburetor has a lever coming out of the top that swivels to open and close the choke plate.

There is another lever that comes out from under the engine cover, which is part of a flap, contained in a molded box on the underside of the cover.

I would expect that it would have a thermostatic spring or some sort of actuator, but but I can't find a schematic or any listing for parts.

Any suggestions?

Here is a link to the part diagrams.  I couldn`t see anything missing, but hopefully they will help out.

https://www.partstree.com/models/cc-98-m-12a-98m7010-cub-cadet-walk-behind-mower-2013/5p70m0b-carburetor-1/

At a guess, it's all there and the flap is air operated off of the cooling fan to turn the choke off once the engine is running. 

Surging is probably being caused by the carb jets being dirty.

The surge is definitely due to the choke opening and closing. Whether it's possible that dirty jets are causing that to happen, I don't know.

In reply to Floating Doc (Forum Supporter) :

Cold engines require more fuel to run, that's why we choke them.

So it starts on the choke, RPMs come up and the flap opens the choke but the engine can't get enough fuel from the jets and runs out of fuel. Engine RPMs drop enough for the choke to close. It gets a surge of fuel from the choke being closed and RPMs climb until the flap opens the choke again. Rinse and repeat until the engine temps get high enough for it to stay running with the available fuel from the jets. 

Clean the carb. It will probably take care of the issue. 

Ugh.  This appears to possibly be one of those cheap-a$$ China carburetors.  I have one sitting on my desk, as a paperweight.  Went to start my generator a few weeks ago and it would only run on spray.  Took the whole carb apart, cleaned it, blew out all the passages with compressed air....no dice.  Wasted a whole day messing with it. 

Finally took the number off the side of the carb (it was a "Huayi") and punched it into the googles.  A new carb, from eBay, was $11, shipped.  I sprung for the $13 one, that included a new fuel filter, spark plug, and gaskets.  Bolted the new carb on, turned on the gas line, and the generator started first pull, no spray. 

Yep.  Here ya go:

https://www.ebay.com/itm/Carburetor-Carb-For-Cub-Cadet-CC46-CC550-CC94-CC98-LawnMower-951-10765-751-10765/184715212816?hash=item2b01e27810:g:P6YAAOSwSQ1gUia7

The fact that Cub Cadet is selling them for 4x that is morally repugnant.  They probably bashed that whole mower together for under $50.  The Cub Cadet name is garbage anymore. 

Thanks, I'll try the eBay carb

X 2 to Volvoclearinghouse recommendation on replacing the whole carb.   My Ariens snowblower was running like garbage a few months back, the carb is a PITA to get to because of the preheating shroud they install around it for winter use.    After pulling it and cleaning it very carefully and still having it run like E36 M3 I found a whole tune up kit including the carb, fuel filter, primer bulb, spark plug and gaskets for $18 bucks / free shipping on the 'zon.    It was the exact / identical carb as the factory one and once installed it ran better than it has in quite a while.

In reply to 11GTCS :

The crazy thing was, I found another link to the carb for my generator on Ali Baba.  It was like $4, but there were shipping costs, and it was coming via the slow boat from China.  I'm staring at this carb right now, and I cannot for the life of me figure out how they can sell it for $4.  Production costs there must be exponentially less.  Just staggering. 

That looks like one of the air/thermostat choke things.  They're remarkably simple in engineering, but complex in the linkage.

It typically uses the fan on the flywheel to push on the flap.  The flap pushes the choke open after it starts running.  The thermostatic coil part adjusts how much the choke applies in its range based on the heat from the motor.  Otherwise it would fully choke when it stops and you try to restart it hot.

If you have dirty jets causing a surge, it will cause the choke to partially apply as the RPMs drop because the fan isn't blowing hard enough on the flap.

Chinese carbs are hit or miss.  I bought one for a Stihl weed wacker that was ridiculously perfect out of the box.  I didn't even touch the high or low mix screws.  This is its third season and it fired up instantly.  I also bought one for a Honda 160 on a lawn mower and it was complete junk.  I just cannibalized it for the gaskets and float to rebuild the stock carb which was surprisingly less expensive than buying a rebuild kit.

volvoclearinghouse said:

In reply to 11GTCS :

The crazy thing was, I found another link to the carb for my generator on Ali Baba.  It was like $4, but there were shipping costs, and it was coming via the slow boat from China.  I'm staring at this carb right now, and I cannot for the life of me figure out how they can sell it for $4.  Production costs there must be exponentially less.  Just staggering. 

Alibaba isn't really a consumer site.  It's not where volvoclearinghouse buys a 2-post lift, its where Harbor Freight negotiates to buy 16,000 2-post lifts, or where Home Depot buys 2.6 million knockoff saw blades and leather gloves for black friday.

Alibaba is eHarmony dot com for wholesalers.  It matches manufacturers with distributors.

Edit:  and yes... staggering to know that the part you pay $18 to buy on Amazon is still profitable to the manufacturer at $4 wholesale.  I used to marvel at the fashion district in L.A.  Stuff comes off the boat and goes straight to the stores where you can buy amazing stuff for $10, and right beside you is a buyer for Vera Wang, Joseph Banks, or Saks 5th Avenue looking for things to add to their fall line.  They'll find something, order 10,000 of them, ship them to their stores and charge $150 for the same thing.

I have four unbranded suits that I purchased in the fashion district, had custom tailored, and delivered to my door in L.A. for under $500.  One of them I noticed later on the rack at Macy's with a Chaps label for $450.  Same designer, same fabric, same prick stitch, the works.

Retail. pffft