Topic 'Re: Lawn mower won't stay running' in forum 'Home Improvement' - dslreports.com

Re: Lawn mower won't stay running

Sat, 20 Oct 2012 20:21:06 EDT

Pacrat posted : I love happy endings! Thanks for letting us know the final solution to the problem... too many do not.

Re: Lawn mower won't stay running

Sat, 20 Oct 2012 19:11:06 EDT

quatrix posted : Problem solved. I replaced the whole carburetor with a brand-new OEM part from eBay ($30) and emptied and cleaned the gas tank again. It started on the first pull, sounds good, and even handled the 10-inch-tall grass that had piled up while I was working on the mower. Thanks again to everyone who tried to help.

Re: Lawn mower won't stay running

Sat, 06 Oct 2012 20:55:39 EDT

quatrix posted : It still seems unlikely that there's gunk in the carb when I've been using SeaFoam all along, cleaned it thoroughly, and the mower is only two years old.

What about the mower only starting on the second pull (or just barely on the first one)? Doesn't that suggest something other than the carb?

Re: Lawn mower won't stay running

Thu, 04 Oct 2012 23:24:25 EDT

KrK posted : Also, for small engines, avoid gasoline with ethanol in it if pure gas is available in your area.

And it's always a good idea to try and let the mower run completely out of fuel rather then put it away with fuel in the tank. Not always possible, but suggested.
--
"Fascism should more properly be called corporatism because it is the merger of state and corporate power." -- Benito Mussolini

Re: Lawn mower won't stay running

Thu, 04 Oct 2012 19:20:15 EDT

iknow posted : sometimes diassembling the carb, removing all plastic and rubber, and boiling the carb in water for say, half an hour will loosen junk up, then carb cleaner and an air spray will remove it.

Re: Lawn mower won't stay running

Thu, 04 Oct 2012 18:39:51 EDT

shdesigns posted : Sounds like the jet is plugged or the pump is still not working.

Is this a "quantum" engine? I may have a tank, carb and filter that will fit.

Re: Lawn mower won't stay running

Thu, 04 Oct 2012 18:04:20 EDT

quatrix posted :

said by shdesigns:

Might be worth ordering a new diaphragm and gasket.

Done, no change, and another $4 down. I thought about replacing the tank and carb, but that would cost me at least $70 when the whole mower was only $150.

There's also a new symptom the last few times I tried to start it. Now the mower usually starts on the second pull when it used to start on the first ("start" meaning "run for three seconds and die"). Is that a clue?

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 22:50:44 EDT

shdesigns posted : Might be worth ordering a new diaphragm and gasket. According to the manual part # 795083. Checked ebay and they are available for about $3.

There are also ones with the strainer and spring for about the same price.

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 21:17:15 EDT

quatrix posted :

said by alkizmo:

As I mentionned before, try to run PURE seafoam through the engine, even if it won't keep running, force it. It will make a ton of smoke! but it will clean whatever is along the way.

I'd be more inclined to try this if I hadn't been using Sea Foam all along. I'm obviously not an expert on combustion engines, but after the constant Sea Foam additive and then the concentrated shower of carb cleaner, it seems unlikely to me that carburetor gunk is still a possible cause. Are you sure that burning pure Sea Foam isn't bad for the engine?

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 21:12:22 EDT

quatrix posted : Right, nothing to adjust. It's model 10T502-0457-B1.

»i.ebayimg.com/t/B-S-Tank-carbure···0_35.JPG

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 20:49:10 EDT

mix posted : Looks like you have a stange carb., but just so we are 100% clear here, this lawn mower has nothing that is adjustable it terms of the carburetor or throttle controls? The carburetor has no pilot screw, no throttle stop screw for idling, or a choke arm connected by cable to a throttle lever? There is no inline fuel strainer somewhere between the fuel tank and carb.? It's all non-adjustable?

Does your lawn mower come with a make an model number? You might get some better responses...

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 17:20:51 EDT

mityfowl posted : Yes I do.

Sent from an iPhone :)

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 14:45:33 EDT

Pacrat posted : You do mean Briggs & Stratton, don't you?

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 13:47:48 EDT

mityfowl posted : Briggs and Stanton is just a name now.

I'll show you my 30 year old B & S.

1 new diaphragm.

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 13:43:57 EDT

mityfowl posted : I think that you need to replace that little carburetor diaphragm.

Re: Lawn mower won't stay running

Mon, 24 Sep 2012 13:19:26 EDT

alkizmo posted :

said by quatrix:

A couple of people mentioned Sea Foam. I've actually been adding a little of that to the gas every since I bought the mower.

As I mentionned before, try to run PURE seafoam through the engine, even if it won't keep running, force it. It will make a ton of smoke! but it will clean whatever is along the way.

I'd try to pass 1-2 ounces of pure seafoam.

Re: Lawn mower won't stay running

Sun, 23 Sep 2012 18:35:51 EDT

quatrix posted : Still no luck. I sprayed carb cleaner everywhere and immediately flushed the plastic parts with water. After reattaching the tank (which was significantly easier than the first time, thanks in part to a socket set), it still won't run.

A couple of people mentioned Sea Foam. I've actually been adding a little of that to the gas every since I bought the mower.

Re: Lawn mower won't stay running

Sun, 16 Sep 2012 13:55:04 EDT

sempergoofy posted : I had a similar thread to this one back in 2009. You might find some good pointers in it.

»Push mower engine trouble

Epilog on that story is that in the next season after that one, it went bananas while I was using it one day. Never started again. Took it to the dump and bought a replacement self propelled push mower that I like better. :)
--
nohup rm -fr /&

Re: Lawn mower won't stay running

Sat, 15 Sep 2012 20:58:30 EDT

alkizmo posted :

said by quatrix:

where the carburetor is built into the tank. I guess I'll take it all apart again tomorrow and follow this guy's instructions.

That's intense.

Before I'd go to that extent, I'd drain all the fuel, make sure there is no more fuel ANYWHERE.

Then I'd pour in ONLY seafoam in the tank (Maybe a quarter of a can of seamfoam) and force the engine to go through it. This will force the seafoam into the carburator and clean it up (Just like spraying carb cleaner into the carb).

Re: Lawn mower won't stay running

Sat, 15 Sep 2012 20:47:07 EDT

mix posted : Gee I wonder what carb cleaner does to rubber and plastic parts...

Re: Lawn mower won't stay running

Sat, 15 Sep 2012 19:48:48 EDT

quatrix posted : Arrrrrrgggggghhhh. It took me more than an hour to get the gas tank and what I THOUGHT was the carburetor off. They didn't make stuff easy to get to.

After all the trouble taking things apart, I couldn't find the parts referred to in YouTube how-to videos. There's nothing resembling the bowl or main jet. And everything that I COULD find and reach looked spotless, so I didn't even bother with the carb cleaner. I at least drained the tank and put in fresh gas while I had it off. I put everything back together, and not surprisingly, it wasn't any better than before.

After some more research, I think I have one of these:

»www.youtube.com/watch?v=Gg4OWXW520k

... where the carburetor is built into the tank. I guess I'll take it all apart again tomorrow and follow this guy's instructions.

Re: Lawn mower won't stay running

Thu, 13 Sep 2012 20:03:57 EDT

shdesigns posted : Yes, the carb will be behind the air filter and have the primer bulb on it.

Re: Lawn mower won't stay running

Thu, 13 Sep 2012 18:54:18 EDT

quatrix posted :

said by 8744675:

Sometimes tilting the mower back and forth on the front wheels and back wheels, and letting it drop several times to give it a jolt will release the float or unclog it enough to mow the lawn.

Sounds like our previous mower that had similar problems before we replaced it. At one point the engine would die if it was tilted just slightly forward when going down an incline. When it sputtered I tilted it on its back wheels and the engine recovered.

Is the carburetor the small part with the air filter on top and the primer button on the front?

Re: Lawn mower won't stay running

Thu, 13 Sep 2012 17:25:54 EDT

Jimdaboe posted : It's a plugged jet hole in the carb bowl bolt. Unscrew the brass bolt at bottom of the aluminium carb bowl. Clean out the holes in the bolt (one passage down the middle and either 2 or 3 side holes). You can use a small wire or paper clip. clean out the bowl and reinstall. Done!

Re: Lawn mower won't stay running

Thu, 13 Sep 2012 17:07:07 EDT

8744675 posted : Probably a gummed up carb or the float is stuck up. My old mower used to do it all the time. Enough gas seeps in to fill the carb bowl, and when you start it the gas in the bowl burns up and it dies because the float is stuck or gas can't flow through the gummed up holes fast enough to keep it running.

Sometimes tilting the mower back and forth on the front wheels and back wheels, and letting it drop several times to give it a jolt will release the float or unclog it enough to mow the lawn.

Re: Lawn mower won't start

Thu, 13 Sep 2012 10:41:55 EDT

quatrix posted :

said by alkizmo:

I don't know if you had a long gap between the last time it ran successfully and now. It's possible the carb got gummed up from old fuel while sitting in storage.

It had only been a week. I have to mow frequently here in South Florida where it's hot and wet all year.

So it's almost unanimous then. I'll get some carb cleaner and a YouTube crash course on how to use it. If that doesn't work then I'll just have it professionally serviced. There are some black specks at the bottom of the gas tank and it's overdue for oil and blade maintenance anyway.

Thanks.

Re: Lawn mower won't stay running

Thu, 13 Sep 2012 10:29:34 EDT

natedj posted : n/m

Re: Lawn mower won't start

Thu, 13 Sep 2012 09:39:39 EDT

alkizmo posted : I second shdesigns' gummed up carb assumption.

I don't know if you had a long gap between the last time it ran successfully and now. It's possible the carb got gummed up from old fuel while sitting in storage.

My B&S mower was barely a year old, but one single winter in storage without draining the fuel and it wanted to die in the spring. My hedge trimmer was worse off, it would stall seconds after I turned off the choke.

Here was my solution (And do an oil change while at it):

1 - Drain all the old fuel from the tank and fuel line (If you can't/don't know for the fuel line, just keep pulling the string until the engine won't even react).

2 - Find the carburator (Usually it's behind the air intake/filter, so remove that).

3 - Spray carb cleaner (I used aerosol seafoam) into it, make sure the butterfly valve is opened up (Hold the handle down as if the engine was running).

4 - Pretend to start it (Pull once or twice). It might even start for a few seconds. Don't worry about the smoke

5 - Spray more carb cleaner

6 - Let it sit for a while

7 - Now put just a bit of fresh gasoline in the tank and start it without the filter box in the way.

8 - Let it run and a couple of times a minute spray more carb cleaner while it's running.

You should be good to go. If not, you need to dismantle the carb and clean it up.

From now on, never fill up the gas tank.
Always put the minimum quantity you think you'll need to get the job done for that one day. You never know if you'll have a drought and that the grass won't need to be cut for a month or two.

Long gone are the days that you just filled up the gas tank every time and never worried about the age of the fuel :p

Re: Lawn mower won't stay running

Wed, 12 Sep 2012 22:00:13 EDT

Pacrat posted : I suspect it's debris in the fuel line/carb. It's amazing how easily leaf/grass debris can enter the fuel system. Some years ago, I had a Cub Cadet tractor that suddenly started to cough and wheeze, then quit out of the clear blue sky. No problem at all in getting it started, but after a few seconds or a minute it would sputter to a complete "cardiac arrest". Baffled the hell out of me. I cleaned the fuel filter, blew out the fuel line, cleaned the carb, used fresh gasoline... nuthin' worked. The gas tank on my Cub was sort of a translucent white and just on a hunch, I put a bright light under it while looking into the fill hole. Damned if there wasn't a dark shadow where there shouldn't be. After using a siphon pump to remove the gas (most of it anyway) I could actually see part of a maple leaf on the bottom of the tank. The outlet was also on the bottom of the tank and what would happen was the leaf would float/drift around until it got close enough to be pulled over the outlet hole... completely cutting of the flow of fuel. With the engine off, the vacuum would release, and the leaf would just "float" away, allowing the flow of gasoline once more. To verify my apparent diagnosis, I started the tractor, and peered into the gas tank. What I saw was the leaf bit slowly work its way over the outlet hole and the tractor would sputter to a stop. I drained/removed the remaining gasoline and fashioned a "sticky stick" and managed to pull the leaf shard out of the tank. Upon the removal of the foreign material, that Cub purred like a kitten! Now, I'm almost anal about making sure the area around the filler cap is completely clear of any dust or debris before I take the cap off to fuel the Cub. I suspect you have a variation of the same problem.
--
Keep your eye on the ball, your shoulder to the wheel, your nose to the grindstone, and your ear to the ground. Now, try to work in that position!!!

Re: Lawn mower won't start

Wed, 12 Sep 2012 18:59:39 EDT

dcurrey posted : Had same problem with Lawnboy. Since I don't know squat about small motors had it professional cleaned. Same problem about year later. About month into season. Think it turned out to be cased by bad gas. No I don't keep gas around year long.

Second time around added fresh fuel with fuel stabilizer added. When I little heavy on the stabilizer. (It was this is going to work or I am getting new one anyway.) Keep starting in and pressing the primer bulb just before it would die. It starting running longer and longer. After about 15 to 30 minutes of this it stayed running.

Been over 1.5 years now and no further problems. I keep fuel stabilizer in all my gas for my mowers now.

Don't buy gas from that station anymore.

Re: Lawn mower won't stay running

Wed, 12 Sep 2012 18:16:42 EDT

SparkChaser posted : Have a year old JD walk behind and it had similar problems. It was dirt in the carb.

OT - but the JD walk behind we had for 15 yrs was 100X better than the new one. I noticed the local JD store selling Hondas :huh:

Re: Lawn mower won't start

Wed, 12 Sep 2012 17:55:49 EDT

shdesigns posted : Most likely a gummed up carb. Second cause would be bad coil.

Lawn mower won't stay running

Wed, 12 Sep 2012 17:19:06 EDT

quatrix posted : We have a two-year-old Yard Machines / Briggs & Stratton walk-behind mower that hasn't really been maintained in those two years. It was running fine until a few days ago. The engine still starts consistently but now dies after a couple of seconds. Today I replaced a blackened spark plug and dirty air filter, but it didn't help. The oil looks fine. What else could be the problem?