Lawnmower won't start; now what do I do?

[Nuje]

After having a nice couple of drinks to "think", nothing has come to me.

Canadian Tire Yardworks mower with 6HP Brggs&Stratton engine. Used it a little over a week ago, and it started up fine, considering it was the first use of the year. Sputtered a bit occasionally (figured I just had some water in the fuel a bit).

But today, can't even get it to fire up - maybe I get a fire or two, but it won't catch. Never done mower maintenance before, so I don't even know where to start.
(New sparkplug...?)

[57]

Each year before I tried to start my lawnmower, which was a 30+ year old Lawn Boy (early 1960's), I would take out the spark plug, clean it and gap it properly. Then clean the "magneto" (the item that provided the spark) - not sure if today's mowers have one. I checked the air cleaner and cleaned it if necessary. I also stored the mower in the fall with about 1/3 a tank of gas and then filled it up in the spring, so that mostly "new" gas would be available for it to burn. (Some people run their mowers out of gas, or use a stabilizer, but I never found it necessary).

The thing was beautiful. If I did the above, then primed it a couple of times, the thing would start on the first pull each spring. If I didn't do all the above, then it wouldn't start until I did - I guess it was a bit of a ritual.

The Lawn Boy never did fail, but I gave it to charity 14 years ago when I bought a cordless electric, which has required no maintenance, other than the occasional blade sharpening which I do with a file. I haven't even needed to replace the battery yet.

[ScaryBob]

As 57 said, routine annual maintenance is necessary. That includes cleaning/changing the air filter, changing the fuel filter (if there is one,) checking/cleaning the spark plug (replace if necessary,) draining the gas tank in the Fall (run 'till empty,) buying and filling with fresh gas in the Spring (unused gas can go in the car in the Fall if not mixed with oil,) checking/sharpening the blade (use extreme caution when doing this yourself,) changing the oil. Most small engine repair shops will do this for $50 plus parts. There are probably lots of online instructions that can be googled.

In this case, I would also drain and clean the carburetor to get rid of any accumulated water.

[Danster]

Here's something to check:
Remove spark plug from engine block then insert it in the plug and make the tip touch in a way where you can see the spark. Be careful not to touch anything with your bare hands. With the plug against the metal, pull the cord to see if you have a spark. If it's faint and blue, you're not bad. If it's orangy colored, we have to go further. I'll wait out..

[Jake]

Remove spark plug from engine block

I would just like to add take a look at it and see if it is wet with gasoline. If it is you have confirm 1 of the 2 requirements, fuel. The other being spark. If no spark then check that the safety bar is engaging properly (one one you must hold down or else it kills the engine).

[KingBuzzo]

I have a cheap POS Canadian Tire mower that never starts until the 20th pull...

I even took it in for service and it made no difference.

I'm no expert but I found my own solution by accident. After cleaning the blade I put the mower upsidedown for less than a minute. After putting it right-side again, it starts first pull!

I think maybe there is something wrong with the carb/float or maybe it isn't getting enough fuel.

Anyway, that worked for me....

[ScaryBob]

We have a Craftsman with a Briggs and Stratton engine. I starts on the first pull every time, even the first time out in the Spring. It has always been serviced annually.

[Bent]

I have found I get the best results from mine (mine has no choke, just a primer button/pump) for a cold start when the tank is completely full.

[Nuje]

Well, being the curious type, I started unscrewing nuts and bolts to find see what I could see, and it would appear that the issue would be with the "auto-starter" (it's simply a wound spring that engages the drive wheel of the motor (I have no idea what the proper names are for any of this stuff - sorry); when you pull the handle to "engage", it releases the spring, which spins the motor to fire up).

Anyway, as I pulled things apart, I found that one of the auto-starter mounts (near where one side of it is screwed to the engine block) broke - snapped a piece of billet aluminum?!

I got to the point of the top of drive shaft exposed, and there was quite a bit of play as you rotated it; there wasn't any side-to-side slop, but if you just rotated it lightly, it would rotate maybe 15 degrees either way with zero resistance, then you could feel it engage the blade (i assume/think).

I'm guessing this isn't a good/normal thing (?).

So, I think at best, it's a new starter thing (or see if I can bypass it somehow); or the engine is cooked.

Is LawnBoy still making mowers?

[Danster]

When you rotated your driveshaft, was the plug still on?

[57]

Good question Danster. Just so I never forgot, I always unplugged my spark plug wire on my LawnBoy immediately after each use and plugged it back on just before the next use. Don't want the unit starting at any time except to cut grass. This also allowed for safe cleaning under the mower after cutting if the grass was a bit damp.

Don't know how easy it is to remove the spark plug wire on the OP's particular mower.

[stampeder]

Nuje, the Yardworks models used to have Tecumseh engines - yours is a Briggs & Stratton?

Originally Posted by nuje

I found that one of the auto-starter mounts (near where one side of it is screwed to the engine block) broke - snapped a piece of billet aluminum?!

And its off warranty now, right? I thought your mower might be having vapour lock or carb problems so I originally posted this:

So far after reading through this thread I'd assumed that the engine was not simply flooded. If it was, you'd be smelling raw gas quite heavily. If that is not the case and you've determined that there is a spark going to the plug, then it would seem that the carb is dry probably due to a vapour lock in the fuel line.

Tip the whole mower on its side so that the fuel tank is above the motor and hold it there for a minute so that any vapour lock bubble has hopefully floated to the top. Shaking the whole mower a few times helps. Put the mower back on its wheels and remove the air cleaner cover, then drizzle a tiny bit of good gasoline in there and cover it again.

Now give it a pull or two and it should ignite from the fumes of the wet air cleaner and cough/sputter a bit as it pulls fuel from the fuel tank and breaks the vapour lock.

[Nuje]

Well, being that I've smacked a fair number of rocks or whatever in its life, and it was starting to backfire and buck on start-up (here I thought it was just getting cranky with its old age), I think I've found what the issue might be: broken flywheel key.

http://www.repairfaq.org/sam/lmfaq.htm#lmlmwnsa

Good write-up. Now, off to find a lawnmower flywheel key store.

[dogpatchkid]

an electiric mower

[barter]

Take out the sparkplug, spray in some wd40, reinsert plug, full choke, and pull the cord.

I have done no maintance on my lawn mower in 15 years, just turn on the choke and start pulling the cord, starts after 5-6 pulls. Left it outside last winter with a garbage wraped around the motor.