Lawn Mower trouble - please help

[andy10917]

I have no idea where the post went. It was long and answered all my questions. My post is in response. I got an error message when I tried to approve it, and now it's gone. The text of it was:

K&N, et. al:

El cheapo mower with Briggs and Stratton engine describes it well. Lol.

I'm not mechanically savvy at this point in time. Maybe someday, to some extent, learning a little as I go. However, my uncle is an expert mechanic who no longer works on engines due to an issue that prevents him from doing so. He's been advising me as well. His advice was in line with that offered here.

Thank you for the info and photos.

Update: I've started and run/used it a bunch of times this evening. Sometimes it's still terrible and barely starts and runs poorly; other times, I think I'm starting to the beginning of improvement from the Seafoam I started using yesterday. All from today.

Answers to Andy's questions:

It's a Craftsman 21" push mower with 190cc Briggs and Stratton engine. It's 3 years old, and has never had any maintenance, other than oil changes, cleaning, blade sharpening, air filter replacement, and spark plug replacement (both several times).


The engine does at times emit smoke. Typically, this is at start-up, but not every time. It has been doing so once every few starts, even last Fall before I noticed any hard starting/stalling/sputtering behavior. The smoke is typically blue when it happens. It did happen today.

"Does the engine run at a steady pace right from the start, or start off well and then fade after a few seconds?"

Currently, it doesn't even necessarily start off well. It has been sputtering at start-up for the past week. Starting last season, I noticed some temporary stalling once at each start-up. Back then, it was starting strong, then fading to nothing, then coming back and was ok. However, I also noticed some...jerking...for lack of a better term, for a long time now. In other words not 100% smooth when running. If it was on the driveway, that slight jerking would cause torsional imbalance, and the mower would tended to turn a tiny bit.

"Has the engine sound become very muffled this year?"

At this point, the engine is noticeably muffled compared to when it was new. Sometimes, it's worse than other times. The past week or two, it has gotten noticeably more muffled. Also, now that the blade rpm is running at varying degrees of lower-than-normal, I can hear the grass tearing (like a shearing sound) when mowing. Also, I hear a bit of a clattering sound as the blade rotates, but this isn't loud or noticeable. My guess is that it always did that, just that it's easier to hear now.

I never let the oil get too low. however, I probably went too long before changing it this last time.

"Was the onset of this problem sudden or gradual? Was everything 100% last season?"

A bit of both. Again, based on my comments from above, there were some minor symptoms last Fall. Also, it's likely that the rpm was starting to decrease then, but I didn't notice it until it hit a certain difference threshold.

"Have you inspected the underside of the mower for wrapped-up string, dried caked grass etc?"

Yes. It's clear.

[Green]

Yes. I posted a detailed reply.

[Green]

Andy...

Can I repost the reply for others to see? Was the issue the link I included to a Sears page showing the mower?

[andy10917]

No problems with your post. I'm not sure, but I may be the only one approving posts tonight, and I got an error when I tried to approve it. I had the text of it and posted it, but I'd love to see yours just to make sure...

[Green]

Ok, so there was a problem with the post. It's because the link I included for my mower is a link to a product that apparently is no longer sold.

Andy, thanks for reposting the text of it.

[andy10917]

Hmmm. I guess I'm not alone.

[g-man]

I would check your oil level. Make sure it is not above the mark (too much). If you ever had too much oil (air filter had oil), it will cause some of the problems you describe. I found this you tube video that shows how to clean it. (The mower in the video has an extreme amount of oil). https://youtu.be/E93phoyAfSw

[ken-n-nancy]

K&N, et. al:

El cheapo mower with Briggs and Stratton engine describes it well. Lol.

Given that information and the symptoms you're seeing, I'd definitely suggest removing the bowl nut and cleaning out the orifice in it. There is almost surely no fuel filter on your engine and any little flake of metal or little piece of grit or little piece of plastic which gets in to the fuel will eventually make its way into that passageway and partially clog it. I would be surprised if that doesn't fix your problem.

I wish I lived closer to you and come over to help -- we could do the above in about 5 minutes and probably have you running again just fine.

[andy10917]

K&N, I gotta disagree some. My experience is that when the float bowl sits for a week, the mower will run well for a bit until the debris blocks again, and then the engine falters. That's why I asked the question about whether it starts OK at first. Green said No.

[PSU4ME]

You sure the exhaust/muffler isn't backed up?

Also, The terrible cut leads me to believe that the blade speed is suffering and that could be from a fuel issue as mentioned or a lack of power. If its 3 years old and its smoking blue already, could the rings be worn out?

[ericgautier]

Question, do you keep gas in it all the time? Or do you run it dry before storing it?

[ericgautier]

The lawn mower isn't working very well lately, and it's getting worse. The last few days, it almost doesn't turn over when starting. It's been tough starting since sometime last Fall...it would stall a bit, but then finally turn over. Now it sputters for a while, never reaches full rpm, and the cut quality is terrible, even when double mowing.

Sounds exactly like what happened to mine.

k-n-n's suggestion fixed my issue - viewtopic.php?f=7&t=22704#p309028

[Green]

I typically do not use up all the gas...except before Winter storage. So, there's typically a little in the tank, or at least some in the line at all times, even if the tank runs out.

[Green]

Today, at the first start, the engine was really rough again; lots of trouble starting and not smooth or high enough rpm. Letting it sit a minute or two did not allow me to start it...maybe the engine was flooded. (This is something that has happened since day 1.) Letting it sit over 5 minutes, allowed it to start. It was hesitant, but after a couple of minutes, seemed to be running ok (but not perfectly).

When I stopped it at the end, a puff of blue-gray smoke came out.

[g-man]

^ other than mowing, have you done any of the troubleshooting we recommended? Ie too much oil?

[Green]

I never allowed the oil level to get too high. The air filter was changed several days ago. I didn't see anything oily on the old one...just some grass clogging it.

[g-man]

Blue gray smoke is oil being burn. It is not a good sign. Since you said the filter area was clean, then there is no oil being introduced into the carburator. Did you notice the blue smoke only at the end and not during? It could be hard to see during. Any steps from now will requiere some mechanical knowledge. I think you should have it looked at.

[Green]

Yes, the smoke only happened once, when I stopped the mower when I was done. The only other time I've seen it has been occasionally upon starting.

Since putting Seafoam into the fuel, I smell an ethanol sort of smell in the exhaust while mowing.

[imauafan]

I've noticed a smell from my leaf blower after adding seafoam to the tank. I couldn't say what it smelled like but it was a different smell that I attributed to the seafoam.

[Green]

Mower started really poorly again today. That was after cleaning the (one-week-old) spark plug. However, once it got going, it seemed to run pretty well. Rpm seemed pretty good. Got another puff of blue-gray smoke today when I shut it down.