What's wrong with my lanmower?

[Patch]

I fired up the lawnmower today to get the lawns trimmed before the rain hits later tonight. It's the second time I've had the lawnmower out and about since last fall. The first time, about 3 weeks ago, went well. Today the back lawn went well. When I moved the lawnmower around to the front lawn and fired it up, it went

VroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroom

non-stop. I checked the air filter (fine), gas (fine), and started it again. It ran fine for about 30 seconds, then started into the up-down cycle again. It worked and allowed me to get the lawn mowed, but I'm wondering what this means? Is my mower dying, or is this easily repairable?

Craftsman Model 917 4.5 hp gas mower, about 5 years old.

[Princhester]

Is it wireless or cabled? A lanmower will choke up on the cables if you try to trim a cabled lan.

[Patch]

Originally Posted by Princhester

Is it wireless or cabled? A lanmower will choke up on the cables if you try to trim a cabled lan.

I do not understand what you mean by this.

[Silophant]

Ethernet cables are 8 24 gauge wires and a bunch of insulation. You run a lanmower over those, they'll get all tangled up in the blades and stop the engine.

[Harmonious Discord]

I'd say it's a restriction in the gas flow somewhere or water. Clean out the fuel lines and drain the gas tank. It could be other things but that would be my first check. Drain the fuel bowl too.

[Patch]

Originally Posted by Harmonious Discord

I'd say it's a restriction in the gas flow somewhere or water. Clean out the fuel lines and drain the gas tank. It could be other things but that would be my first check. Drain the fuel bowl too.

Could it be gas quality at all, since it's been sitting a while?

[Harmonious Discord]

Originally Posted by Patch

Could it be gas quality at all, since it's been sitting a while?

It could be debris or water in the gas. Water rolls around on the bottom of the tank and gets sucked in small globules at a time. I've seen it happen so you get the cycling speeds. Pure gas full speed. Water arrives and it slows down. Gas arrives and you go full speed again. It can be your gas can has water in the bottom and you filled the working mover with water contaminated gas.

[FoieGrasIsEvil]

Does it have a choke? Did you leave the choke on somehow, or inadvertently knock it into choke position when you moved it to your back yard?

[Tero1111]

Change the air filter. I always do that. Then I take it to the repair shop.

[Shagnasty]

Originally Posted by Silophant

Ethernet cables are 8 24 gauge wires and a bunch of insulation. You run a lanmower over those, they'll get all tangled up in the blades and stop the engine.

Correct. I work in IT and lanmowers are pretty useless when in a wet area. It shreds plastic and wire all over the place and will destroy the engine. They are dangerous to have around too because some janitor is going to decide to have some late night fun and cause millions of dollars worth of damage in the blink of an eye. I usually just get a bunch of high school kids cut it with scissors for all the trouble it takes to bring a large company to its knees.

If the lanmower is just having standard engine trouble, the testing and fix is the same as the equipment you find in other applications like go-karts and landscaping. Drain the gas, check for obstructions in the deck, clean the air filter, and then check the spark plug for fouling if you need to. It is most like the gas or the air filter which anyone can do themselves if you look at the manual. I have had good luck just by burning off some bad gas and adding more as you use it but you can just flip it over to drain it quickly. Don't use your lanmower anywhere other than your own home though. There could be serious charges in some jurisdictions. I don't even know why Home Depot sells them.

[Patch]

Originally Posted by FoieGrasIsEvil

Does it have a choke? Did you leave the choke on somehow, or inadvertently knock it into choke position when you moved it to your back yard?

It has a little rubber button you press 3 times, then pull the starter cord. I can check if it's stuck, along with the other suggestions.

[Harmonious Discord]

Originally Posted by Patch

It has a little rubber button you press 3 times, then pull the starter cord. I can check if it's stuck, along with the other suggestions.

I worked where they made the parts for those small engine primers. They don't get stuck. You could break the plastic gas line connector off or tear the material, but that would be obvious and not stuck.

[Patch]

Originally Posted by Harmonious Discord

I worked where they made the parts for those small engine primers. They don't get stuck. You could break the plastic gas line connector off or tear the material, but that would be obvious and not stuck.

That simplifies the task list. Thanks.

[cornflakes]

It sounds like there is water in the gas. Remove the carburetor float bowl and drain the tank into a glass container. It will probably look like there is a puddle of something at the bottom of the gas--that is water. Better yet, just replace the gas. Even better yet, use sheep to cut your lan--they take longer but trim it evenly so that everyone has a comparable connection speed no matter where they work in the building.

[Tabby_Cat]

Try disabling and re-enabling the Dual Hose Carburetor Pulse (DHCP), and if that doesn't work, try disabling the Neutral Alignment Transmission (NAT), those are the usual culprits when lanmowers go bad.

Or you could try putting your lanmower into De-Mulch Zoning (DMZ), although that's a little risky. Don't operate in DMZ mode for too long.

[Princhester]

Originally Posted by cornflakes

Even better yet, use sheep to cut your lan--they take longer but trim it evenly so that everyone has a comparable connection speed no matter where they work in the building.

I don't recommend it. They drop packets all over the place.

[Dereknocue67]

I had a lawnmower that did exactly the same thing and corrected it by adjusting the 'lean/rich' screw at the carburetor. See your manual to locate and adjust it.

Another potential cause is a gummed up carb that can be cleaned with most carburetor cleaner sprays.

[xash]

Originally Posted by cornflakes

Even better yet, use sheep to cut your lan--they take longer but trim it evenly so that everyone has a comparable connection speed no matter where they work in the building.

The only problem is that sheep mow up the lanscaping.

I once hired Mowery's sheep to do this for me, but she had a little LAN, little LAN, little LAN, whose IP lease was white as I/O, and everywhere Mowery went, the LAN was sure to go.

It followed her to spool one day, spool one day, spool one day, and made the children Plug and Play, Plug and Play, Plug and Play, to see LAN at the spool that day.

And that's the story of LAN and Mowery.

[Harmonious Discord]

Since it was fine for a number of mowings this year and suddenly developed this problem I suggest he not touch the carburetor mixture screw.

[Khendrask]

Originally Posted by Harmonious Discord

Since it was fine for a number of mowings this year and suddenly developed this problem I suggest he not touch the carburetor mixture screw.

Agree. Water in the carb/gas would be my number one thought, so drain it completely, and try fresh gas. Particularly if you last fueled it up with a gas containing ethanol, as it holds on to water like a sponge.

The second most likely on my list would be bad o-rings in the carb / fuel system, or even pinhole leaks in the hose delivering the gas to the carb, allowing air into the fuel.

The third most likely, though way down the list with current gasoline formations would be fouling from having the gas turn to 'varnish', which will definitely clog up the fuel system. Modern gasoline though is very good at remaining stable for 6 months to a year with virtually no degradation except color.

[aruvqan]

Originally Posted by xash

The only problem is that sheep mow up the lanscaping.

I once hired Mowery's sheep to do this for me, but she had a little LAN, little LAN, little LAN, whose IP lease was white as I/O, and everywhere Mowery went, the LAN was sure to go.

It followed her to spool one day, spool one day, spool one day, and made the children Plug and Play, Plug and Play, Plug and Play, to see LAN at the spool that day.

And that's the story of LAN and Mowery.

coffeesnarf

[Sparky812]

Originally Posted by Harmonious Discord

Since it was fine for a number of mowings this year and suddenly developed this problem I suggest he not touch the carburetor mixture screw.

Ditto, don't touch the mixture, if you run the engine too lean you will damage the piston.

Is it a 2-stroke or 4-stroke?
You need 3 things for your engine to run spark, gas, and air. You're obviously getting spark and it sounds as if you may be either starving for gas or choking for air.
Replace spark plug to insure you are getting a proper spark.Does it run better?
Take the air filter off, is it wet?
Check the choke and blow out the carb. Try running the engine with the air filter and choke open. (be careful not to get anything into the carb). Does it run the same?
If not, try using a carb cleaner and fresh gas.

[Philster]

Ethanol fuel? It sat a while?

Drain fuel.

Add fresh fuel with a product that treats fuel for water, ethanol and adds stability. "Stabil" is one brand.

[Mr. Duality]

It could be that the gas cap vent is obstructed. All small engine gas caps are vented to allow air into the gas tank as fuel is consumed. If this vent is plugged fuel flow will be restricted. Loosen the gas cap and see if the engine will run smoothly. Gas caps are cheap to replace.

[Patch]

Originally Posted by Sparky812

Ditto, don't touch the mixture, if you run the engine too lean you will damage the piston.

Is it a 2-stroke or 4-stroke?
You need 3 things for your engine to run spark, gas, and air. You're obviously getting spark and it sounds as if you may be either starving for gas or choking for air.
Replace spark plug to insure you are getting a proper spark.Does it run better?
Take the air filter off, is it wet?
Check the choke and blow out the carb. Try running the engine with the air filter and choke open. (be careful not to get anything into the carb). Does it run the same?
If not, try using a carb cleaner and fresh gas.

4-stroke, and the gas shouldn't be ethanol - at least, no more ethanol than I put in my car (I siphon gas from my tank). I think California runs some ethanol in fuel, but as I mentioned before I've been running this mower for 5 years, and I don't think it's a fuel formulation issue.

Had the fun joy of coming down with a cold last night, so I"m putting repairs off for a few days. I've got a nice list now of things to check. Thanks.

[Omar Little]

Definitely sounds like bad gasoline. Winter gasoline has a higher vapor content than summer gasoline. This may have something to do with it. Drain the gas out and put fresh in and see if that fixes it.

[billfish678]

My neighbors cheap new mower started doing the same thing. I told him to use massive doses of Stabilite gas conditioner/stabilizer till it cleared up, then keep using it from then on at a modest level.

It cleared his mower right up. And its behaved ever since. Those passages in a small carb are pretty small. It doesnt take much in the way of a varnish deposit to really mess things up. And when you are doing the last mowing of the fall, also use a large dose of stabilite in the last batch of gas then run the mower till its out of gas.

[Gary "Wombat" Robson]

Originally Posted by Princhester

Is it wireless or cabled? A lanmower will choke up on the cables if you try to trim a cabled lan.

Originally Posted by Silophant

Ethernet cables are 8 24 gauge wires and a bunch of insulation. You run a lanmower over those, they'll get all tangled up in the blades and stop the engine.

[moderating]
Since this is GQ, we'd appreciate it if you wait until some serious answers come in before you start joking and making fun of the OP's spelling.

Thank you.
[/moderating]

[Surly Chick]

It's winter. It's clearly in hibernation and annoyed that you woke it.

[Gangster Octopus]

It's threads like this that make me happy I have an electric mower.

[lieu]

I'm monitoring this as well as I had a similar problem with my last mower, since replaced. Putting in new gas and most of the other recommendations mentioned above had no positive effect. What was very strange about mine though was that I was mowing along fine (John Deere around 8 years old) one afternoon, bumped into a large landscape rock and all of a sudden it started the fluctuation. Weird, from reliable and trouble free to annoying as hell and nothing I tried would return it to normal operation. Rather than spend hundred(s) to fix that old of a mower, I just bought a new one (Ariens).

[crazyjoe]

Does the carb sit right on top of the fuel tank? I had one like this, and there was a rubbery bladder type of gasket that was between them. After a while, usually a couple years, this bladder would get too stretched out or something and need to be replaced. I could usually tell because it would belch black smoke and run as you described until it was nearly out of fuel, then it would settle down and run closer to normal.

Good luck.

[CannyDan]

Originally Posted by aruvqan

coffeesnarf

Same here. And I was really liking my new keyboard, too......

[LunarPlexus]

Originally Posted by Gary "Wombat" Robson

[moderating]
Since this is GQ, we'd appreciate it if you wait until some serious answers come in before you start joking and making fun of the OP's spelling.

Thank you.
[/moderating]

Those scofflaws preempted all my jokes.

[xash]

Originally Posted by Gary "Wombat" Robson

[moderating]
Since this is GQ, we'd appreciate it if you wait until some serious answers come in before you start joking and making fun of the OP's spelling.

Thank you.
[/moderating]

This post has been mowed by the mowderator*

*I'm assuming the OP has got some good serious responses in this thread and won't mind jokes now.

[flano1]

ahh!

doncha just love the dope!

serious answers and seriously weird, wacky, and wonderful.

i love youse all.

[Gary "Wombat" Robson]

Originally Posted by xash

This post has been mowed by the mowderator*

*I'm assuming the OP has got some good serious responses in this thread and won't mind jokes now.

"Mowderator"? As in,

"Your can is LAN, and I'm the mowderator"?

[Rack-a-Bones]

Originally Posted by xash

This post has been mowed by the mowderator*

*I'm assuming the OP has got some good serious responses in this thread and won't mind jokes now.

Does a mowderator out rank a moderator? What about an Administrator? Does the Angel of Death outrank you all?

As to the OP: I agree with others that the issue is either your spark or the carb. Sounds like it's starving for air.

ETA: It has been almost two weeks. Did it get fixed?

[Bowhunter]

Okay, sorry I missed this thread. I repair small engines for a living. You mower is experiencing what is called a surge. It's caused by a lean fuel mixture. Since it's been sitting for a while, most likely the main jet is clogged with gum, or sediment. There are other causes, but this is the most likely reason. You need to take the carburetor apart and give it a thorough cleaning. This will probably solve your problem. It's a fairly straightforward job.

If your mower has a Tecumseh engine, you may have to replace the carburetor. Craftsman used to use them exclusively. Now they have seen the light, and use a wider variety of engine manufacturers.

Briggs and Stratton, go ahead and clean it. If you feel the need to purchase a rebuild kit, check into a whole new carb. On a lot of Briggs engines, the rebuild kit costs $15, and a new one is $30.

Hope this helps, I wish I'd seen the thread sooner.

[panman_1960]

On a mower this old I have seen the governor spring break.... did on mine. Check that also.

later, Tom.

[Patch]

Funny I get new posts on this thread today. I just got done repairing the mower.

I've been down with a cold/flu/sinus infection for the past few weeks, but the other day I felt better enough to get to work on it. Keeping things simple and within my limited technical expertise, I cleaned the filter, changed the oil, replaced the spark plug, and drained the gas, refilling it with fresh gas mixed with Sta-bil to treat the gas I couldn't get out. This morning I got it all completed and fired it up. I let it run for a few minutes and it sounds just fine with a nice, even tone.

Naturally, today it's pouring so I can't mow anything.

Thanks for all the input. Hopefully this has fixed it and no further repairs are necessary.

[rockypg]

Originally Posted by Princhester

Is it wireless or cabled? A lanmower will choke up on the cables if you try to trim a cabled lan.

Hmm. Your ideas are intriguing to me and I wish to subscribe to your newsletter

Originally Posted by xash

The only problem is that sheep mow up the lanscaping.

I once hired Mowery's sheep to do this for me, but she had a little LAN, little LAN, little LAN, whose IP lease was white as I/O, and everywhere Mowery went, the LAN was sure to go.

It followed her to spool one day, spool one day, spool one day, and made the children Plug and Play, Plug and Play, Plug and Play, to see LAN at the spool that day.

And that's the story of LAN and Mowery.

Hahaha. Epic Thread.

[Projammer]

Sounds like a sticking float valve in the Carburetor.

Basic cleaning instructions

[Darth Panda]

Originally Posted by panman_1960

On a mower this old I have seen the governor spring break.... did on mine. Check that also.

later, Tom.

I have seen the old governor on spring break on a mower... did this also. Mine that check.

[Cheshire Human]

Originally Posted by Darth Panda

I have seen the old governor on spring break...

Tell that old coot to get back to the state capitol and stop hitting on the college chics...

[Magiver]

It can surge because of a vane-air governor moving back and forth (bad spring) or varnish in the carb or a vacuum leak from carb to engine. If you put it away with a low tank of gas than it's very possible that the level was at or near the pickup tube and it varnished on the mesh screen covering the end. look for a broken or disconnected governor spring and then pull the carb and spray some carb cleaner around the throat at pickup up tube. You can scratch the varnish off the screen with your fingernail.

[Magiver]

Video showing air-vane governor
carb repair from same video series

[Patch]

Well, that didn't work. As I mentioned before, I changed out the gas, oil, sparkplug, and cleaned the filter. It ran fine for the back lawn, but halfway through the front lawn it went back into the VroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroomVroom cycle. Interestingly, it did it around the same point it did it last time -- after running about 20-25 minutes.

Next step, when free time appears, seems to be to clean out the carburetor and see if that fixes things.

[jasonh300]

If it was anything like my first mowing of the season, there was little grass and a lot of thatch and dust. Clogged up the air filter in 15 minutes. It's not unreasonable to think that the air filter is clogged up again.

I have a foam air filter and I just clean it really well in the kitchen sink with Dawn dishwashing liquid. Wring it out real good and put a few drops of motor-oil on it and squeeze it to distribute the oil through it and reinstall.

Once I'm cutting grass again and all of the decomposed grass and dust is gone, it's usually good for the rest of the year.

BTW, the only reason I clicked on this thread was because I caught the LANmower typo and wanted to see the smartassed comments.

[Patch]

Originally Posted by jasonh300

If it was anything like my first mowing of the season, there was little grass and a lot of thatch and dust. Clogged up the air filter in 15 minutes. It's not unreasonable to think that the air filter is clogged up again.

No, if you read me response you'll note that I cleaned the air filter. It was fairly clean to begin with, so I don't think that was it.