A neighbor was sorting an older Craftsman brand mower with Kohler engine. There’s a linkage between the business end of the engine and carburetor. I figure it’s for the engine to manipulate throttle since the carburetor has no means to move the linkage other than relaying throttle position. Engine speed changed rhythmically as the linkage oscillated. Is this normal or is something wrong? It can’t be normal for idle to pulse like that. What’s the purpose of that linkage?

Sixto
05 E320 wagon 173K miles

The linkage usually goes to an air vane governor control under the sheet metal blower housing. Air from the flywheel moves the vane controlling throttle/rpm's.

Sometime the vane can get sticky but most often the hunting idle is a dirty or internally leaking fuel control issue in the carb. Check the vane for free movement, check for loose carb mountings causing a vacuum leak. If these fail pull the carb, clean it and put a kit in it with a new needle valve.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

If it is a reasonably current model you might be able to look up the operators manual and even a repair manual on the internet. You also could identify who actually made the mower.

The Sears parts site often has exploded views of the parts for their products. You need the model number to look them up.

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84 300D, 82 Volvo 244Gl Diesel

A new $20 carb fixed it. Tuned out of the box. No telling how many hands and ham fists had been on the old carb.

Sixto
05 E320 wagon 173K miles

New problem after sitting a couple of weeks. Mind I don’t know how these things work so my descriptions are best effort. Starts easily and goes through throttling smoothly. Any load and it stalls. Even with the driven wheels in the air it stalls. Even engaging the cutters with the transmission in N causes a stall. It’ll idle forever even at WOT and the fuel filter never goes dry. I have to guess insufficient fuel but a couple of weeks ago it charged up a 15* incline with the deck set closest to the ground. Transaxle is clean and dry on the outside. I can spin the transaxle input pulley by hand. If I have to guess, I’d say it feels heavier to push in push mode but it rolls along.

Sixto
05 E320 wagon 173K miles

Seat switch came unplugged.

Sixto
05 E320 wagon 173K miles