OK... I guess that'd be considered "fresh".

How about the mower's tank? CLEAN?

And did you remove the carb bowl and make sure there wasn't any debris in there?

Jason and others are more small engine experts certainly than I, but your symptoms sure sound like crapola blocking some passages in the carb. Either that or your choke plate is flopp'n closed...

I cleaned the carb the best I could. If there is some blockage, why is it that the mower runs "normally" with Chemtool but sputters when I fill it with gas (not mixed with Chemtool).

Well, my guess is the cleaner is reducing the combustibility of the gasoline to some extent. This would mean the air:fuel ratio is set too rich in the carb, and when you add the cleaner it brings the ratio into line. (If I'm thinking this correctly...)

I think the main jet is the port visible looking straight up in the center of the float bowl, accessible only by removing the bowl. Some are screw in jets, others pressed in.

I'd take the bowl off, and unscrew that jet. Clean it with a small piece of wire, being careful not to damage it or make the hole bigger. I'd also spray some carb cleaner up the passage where that jet came out.

While I was at it, I'd GENTLY seat any adjustable jets, CAREFULLY COUNTING the exact number of turns (to the 1/16 turn) that it took to seat the jet, and writing this down. Then I'd back the jets out completely, and clean both it and the port it came out of with the spray cleaner. Then reinstall the jet, GENTLY seating it, and backing it back out the previously determined number of turns.

Barring this, I dunno... Wait for an expert to chime in.

I'll try to work on this as per your instructions. THen I'll give a follow-up. Thank you.

I am in more trouble now. After assembling back the carburetor, I pulled the throttle control cable and broke it. Perhaps two years of storage made it rusty. I don't know if this is replaceable.

Throttle control cable is available and inexpensive... Any small engine shop, and indeed many big-box (Home Depot) type stores carry them. Between 5 and 20 dollars.

J

The throttle control cable that I got from Lowe's differ from the original. The z-end of the replacement cables are too thin and does not hold fit into the handle-bar. Sears may have this part, I will keep on looking.

Are you looking for a Throttle cable, or a Deadman/Brake cable? The cable running to the deadman grab bar (bail) is not a throttle cable. Different ends.

J

I believe it's a throttle control cable. The one that broke connects to the carburetor and to the handle bar. I have to pull back the handle bar to keep the mower running, that's where the cable is connectec. THis is an old push mower.
Thanks.

Good catch. I'd missed the reference to the handle bar...

Possible that mower doesn't have an adjustable throttle... Only one cable and as you say goes to the dead-man bar. Engine throttle is one speed - held in place by the governor.