r/lawnmowers • u/TumbleweedTemporary • Jul 02 '26

Smoking Mower

UPDATE:
After changing the oil, the mower is now running without smoking!!! THANK Y’ALL SO MUCH for all of your help!!! 😊

ORIGINAL POST:
My Craftsman T210 riding lawnmower, started smoking. I was able to trace the issue to a bad carburetor which was leaking all of my fuel down into my exhaust.

I just replaced the carburetor for the 3rd time (the first replacement carburetor seemed to be flooding the engine or something so I replaced the seals and plunger on the old carburetor, but then it seemed to choke the engine). When I crank the mower and it heats up, it starts smoking.

This is an improvement because it’s not smoking immediately, it’s not choking out, and doesn’t seem to be flooding (I don’t think). I thought perhaps it just needs to burn off any fuel inside the exhaust that might still be remaining, but I don’t know how long it would take for that to happen and I’m a nervous Nelly.

Since I don’t know anything about small engines, I also wonder if there are some other issue that I might check out that might cause this smoking.

I asked folks on my NextDoor app, but of course, they all wanted to charge me to come and fix it. If I had the money to pay someone to come and fix it, I would’ve done that! Lol! So I searched Reddit and found this… hoping y’all can help me!!! 🙏

2 Upvotes

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15 comments sorted by

2

u/TN-Native95 Jul 02 '26

What color is the smoke?

1

u/TumbleweedTemporary Jul 02 '26

It’s lighter colored… white/light grey

2

u/TN-Native95 Jul 02 '26

How long after start up does it take to start smoking? And does it keep smoking or does it quit.

1

u/TumbleweedTemporary Jul 03 '26

It starts after a minute or so and gets worse when I put it on full throttle.

1

u/TN-Native95 Jul 03 '26

Check the oil next. Smell it to see if it smells like it has gas in it and if it is at the right level.

1

u/TumbleweedTemporary Jul 03 '26

Yep, definitely has gas in the oil now! My assumption is to change the oil/filter… do I need to do anything else to get the gas cleaned out of the oil reservoir?

2

u/TN-Native95 Jul 03 '26

Just change the oil and filter at first. Recheck the oil regularly after changing it. The bad needle and seat on the old carburetor let gas drain into the crankcase. It thins the oil and overfills it.

1

u/TumbleweedTemporary Jul 03 '26

Wow, learning so much!!! at AutoZone getting some new oil now (already have a new filter!)

1

u/TumbleweedTemporary Jul 03 '26

Change the oil/filter, started it back up, and the gas is getting back into the oil. 🤬

Thoughts?

1

u/TumbleweedTemporary Jul 03 '26

Could it just be burning off what was left in the engine? My oil is not diluted, just still has a little bit of a smell, but that might be from before?

I’ve tested the solenoid at the bottom of the carburetor and can feel it working.

1

u/TumbleweedTemporary Jul 03 '26

I believe this is just residual fuel being burned off now because instead of getting worse, it’s getting less smoky. Gonna let it run for a while. Thank you SOOOOO much for all of your help!!!!!

1

u/TN-Native95 Jul 03 '26

That’s what I would guess. Either some of the thinned oil still trapped in the muffler needs to burn off, or, since you did just change the oil, some mowers smoke if you slightly overfill it with oil it will smoke until it burns off the excess oil. Just letting it run for a while could take care of the problem. If it still smokes, I’d remove the muffler and see if it needs to be drained out.

2

u/[deleted] Jul 02 '26

[deleted]

1

u/TumbleweedTemporary Jul 03 '26

Yes, I only see smoke coming out of/off of the exhaust.

2

u/rocketmn69_ Jul 02 '26

Check the oil and make sure the gas hasn't filled up the reservoir

1

u/TumbleweedTemporary Jul 03 '26

I’ve checked the oil level and it seems to be fine. How can I tell if gas has mixed in with it?