Mower won't start

[UrbanWolf]

My family's old mower won't start no matter what we try, new gas, new oil, new spark plug. What other reasons cause it to not start? Is there a battery that make the spark plug sparking like cars?

[Boadie30]

No... what kind of mower? Riding.. push.. a battery would only push a starter.. what about air? How long has it been sitting? Air cleaner? Record with sound trying to start..

[BPTactical]

No battery. Most mowers are magneto off of the flywheel. Usually their timing does not shift, unless the blade struck something.
A variety of reasons it may not start, gummy carb, plugged fuel line, plugged vent in the gas cap, plugged air filter etc.
Systematic approach: are you getting fuel to the cylinder- spark at the head-compression decent.
A whole mess of reasons that are hard to diagnose on da webz!

[twitchyfinger]

Is is a pull start or does it have a starter motor to crank it over? Most likely it's a dirty carb from old gas sitting in it.

[generalmeow]

There probably isn't a battery. If its getting a spark, it sounds like its not getting fuel. Maybe take the carburetor apart to see if its blocked?

[UrbanWolf]

It's a pull start, I'm very curious if it doesnt have a battery, what creates the spark?

[twitchyfinger]

It's a pull start, I'm very curious if it doesnt have a battery, what creates the spark?

Like BP said there is a magneto on the flywheel that generates electricity when it spins. Did you check for spark?

[clublights]

It's a pull start, I'm very curious if it doesnt have a battery, what creates the spark?

Magneto...


http://en.wikipedia.org/wiki/Magneto

[UrbanWolf]

Like BP said there is a magneto on the flywheel that generates electricity when it spins. Did you check for spark?

No, I can hold the spark plug and no shock, took it into the dark, no spark.

[twitchyfinger]

It gets complicated to explain over the net but its basically when you pull start it. Here is a good explanation: http://science.howstuffworks.com/question375.htm

[twitchyfinger]

No, I can hold the spark plug and no shock, took it into the dark, no spark.

You need to have the end of the plug grounded to the engine like on one of the cooling fins of the cylinder head to produce a spark. Also careful if you are not holding the plug by the boot in it you can get zapped pretty good!!!

[w748]

I'd take it as a sign from God that I should go fishing.

[To Bear Arms]

Usually its a gummed up carb. Auto fuel is nasty and gets sticky after a year or so. Pull the air filter off and take the carb off if you can and clean it up with carb cleaner I like to run some carb cleaner thru it and re install. Drain out all the old gas and make sure the supply line to the carb is not blocked.and get some fresh gas and mix in some Sta-Bil. You can buy carb cleaner and Sta-Bil at any auto parts store. Good luck and I bet you will learn something!

[SideShow Bob]

Put the lever to run, pull the plug wire off the plug, hold the tip of the plug wire and give the pull cord a good yank. You will know if it is getting a spark or not.

Then, Put the plug wire back on the plug, take the air filter off and dribble a small amount of gas down the intake above the carburetor throttle butterfly and pull the starter rope. If the mower runs briefly, as mentioned before, the carburetor needs cleaned/rebuilt.

[twitchyfinger]

Usually its a gummed up carb. Auto fuel is nasty and gets sticky after a year or so. Pull the air filter off and take the carb off if you can and clean it up with carb cleaner I like to run some carb cleaner thru it and re install. Drain out all the old gas and make sure the supply line to the carb is not blocked.and get some fresh gas and mix in some Sta-Bil. You can buy carb cleaner and Sta-Bil at any auto parts store. Good luck and I bet you will learn something!

Agreed and I bet there is at least one you tube how to video on mower tune ups.

[colorider]

Clean the carb. Simple to do. blow a ton of carb cleaner through all the passages and jets. My mower had been sitting for 2 years and the carb looked like there was maple syrup in it. I went through a can and a half of carb cleaner getting it cleared out. Don't put gas in the carb to start it, but spray a blast of the carb cleaner in it then pull the pull start. Should get it going.

[UrbanWolf]

You need to have the end of the plug grounded to the engine like on one of the cooling fins of the cylinder head to produce a spark. Also careful if you are not holding the plug by the boot in it you can get zapped pretty good!!!

I did have it ground to the engine.

[BigDee]

When all else fails its never to late to buy a new mower. :)

[twitchyfinger]

I did have it ground to the engine.

Okngood just checking. Then that's when it gets complicated to explain. Most mowers today will not produce spark to start the engine unless you have the bar on the handle depressed (it's a safety feature). They made it that way so you have to be behind the mower to start and operate it for safety concerns. That bar is a cutoff switch to the electrical. I'm assuming you had that engaged also? Like others have said it takes a systematic approach of testing trying and cleaning (like said carb) to diagnose and repair a mower. Kind of difficult to do other than the educated guesses given by everyone so far. Check out all the you tube lawn mower repair vids or if you get tired of dealing with it. A tune up shouldn't be too much at a small engine repair shop.

[UrbanWolf]

When all else fails its never to late to buy a new mower. :)

I think my AR build is getting delayed, again.

[Jim B]

Check for rust on the surface of the flywheel (the part that passes by the ignition coil) and on the ignition coil (the part that faces the flywheel).

[Jim B]

My family's old mower won't start...

How old is "old"? If it's really old, and has points, they could be bad.

[BPTactical]

If your not getting spark and you are not familiar with a magneto system, your in over your head. Timing is adjusted on a magneto by a precise gap measured in thousandths of an inch between the armature(flywheel) and stator(pickup). That's why I made the comment about the blade hitting something, it will either knock the timing off or it can shear the crank key, shifting the flywheel.
A tune up shouldn't be too much, I took mine in last year for a once over and it was 65.00 IIRC and they rebuilt the carb, timed it, new fuel filter and plug.

Oh and the comment on it being Gods way of telling you to go fishing is a wholly valid comment and should be heeded.

[Great-Kazoo]

Clean and redo carb, blade sharpened, oil changed, new air filter LABOR: $50 +parts.

BP mentioned it already. turn mower on side (with carb side down) check blade (with spark plug REMOVED) to see if blade hit something / shaft bent. Putting new gas in it does not always allow your vehicle / mower / internal combustion engine to start. Sitting as long as you said it did, means the diaphragm in the carb , needle and possibly the float are trashed. The diaphragm is a thin rubber like membrane that dries out. Just like fuel line old parts need to be replaced.

FOLLOW one of the many vid's on youtube..for carb rebuilding and tune up.
To rebuild the carb you need mower MODEL, MAKE, SERIAL NUMBER, Engine size, Carb MFG (there are 3-4 different carb mfg)

One of the biggest things people neglect doing it adding a fuel stabilizer before putting up for winter / storage. After time it is not uncommon for a Carb to corrode internally. Which , once other issues are ruled out is more than likely what you have a problem with. Carbs run $50-120.

[Gman]

Take it to a shop that does small engine repair. If it's a Briggs & Stratton, it'll probably run just about forever. Never cared much for messing with Tecumseh engines.

The Sta-bil in the power equipment gas can is cheap insurance that you won't have to worry about your carbs getting gunked up.

[kwando]

Hope this is not the first time you're starting the mower... But my first time EVERY year my OLD mower needs a kick start of starting fluid in order for me to start it. +1 on using sta-bil

[sniper7]

New mowers are cheap. Or Craigslist has plenty of them as well.

[brutal]

If all else fails, I've got an old 3 in 1 (bag, discharge, mulch) clunker you can have if you drive to Parker and pick it up.

It's old, ugly, a little rusty, has a coat hanger for the safety lever wire, the bag is half rotted, but it runs and is self-propelled. I use it to cut the weeds in the way back. Not sure if I can find the plug for mulching. The wife refused to be seen using it so I had to buy her a new fucking Toro she can fuck up in 3 months.

[sniper7]

If all else fails, I've got an old 3 in 1 (bag, discharge, mulch) clunker you can have if you drive to Parker and pick it up.

It's old, ugly, a little rusty, has a coat hanger for the safety lever wire, the bag is half rotted, but it runs and is self-propelled. I use it to cut the weeds in the way back. Not sure if I can find the plug for mulching. The wife refused to be seen using it so I had to buy her a new fucking Toro she can fuck up in 3 months.

Hell...I would buy a new mower every year if my wife mowed the yard!

[brutal]

Hell...I would buy a new mower every year if my wife mowed the yard!

She "likes the exercise" and needs it.

Speaking of which, I need to get after her, it's getting long in the front. The grass that is.

[sniper7]

If she likes the exercise she is more than welcome to cover over and mow mine. You bring her over and we will supervise from the front and back decks with beers in hand!

[Buff]

Take it to a shop that does small engine repair. If it's a Briggs & Stratton, it'll probably run just about forever. Never cared much for messing with Tecumseh engines.

The Sta-bil in the power equipment gas can is cheap insurance that you won't have to worry about your carbs getting gunked up.

If you take it to a shop to be repaired you're looking at least $50.00 plus parts to get it running at a small time shop, if you take it "good shop" like MAC in Loveland you'll pay more but it'll be right which equals more money. Most older used mowers are only worth $50 at the most so paying a shop to repair it doesn't make sense. C-list, or Habitat for Humanity is were I'd look or Sears has basic 21" push mowers for less than $200, depending on how much you have to cut these will do the job just fine and they do hold up. I have two Craftsman mowers one that's about 25yrs old (still runs good) and another I picked up a couple years ago because it had a bagger.
Fuel in Co has a bunch of additives which raises hell with season equipment like mowers, some say use Sta-Bil but I've never tried it. I drain the fuel tank every fall and run it dry. This way all of the additives that gum up the carb are gone and the methanol in the fuel doesn't dry up fuel lines and O-rings in the carb.

[earplug]

Drop the fuel bowl and drain out some fuel. Mine had water built up in the carburetor fuel bowl. Modern gasoline sucks with the ethanol mandate.

[USAFGopherMike]

Couldn't resist: http://www.youtube.com/watch?v=G-tCIRJH9p0

[Stone83]

Wait for the clearance sale on mowers this fall...

[rwg550]

I had same problem with Honda mower. Took it to Big Tool Box where they diagnosed and fixed a stuck intake valve.

[Great-Kazoo]

SO going to mid sept you ever fix the mower? ? ?

[UrbanWolf]

SO going to mid sept you ever fix the mower? ? ?

I took the spark plug out and let it sit for a few days, then i tred to start it again and it worked.