Any Lawn mower techs?

[BuzzStPoint]

Stummped on this one.
I have one of those cheaper Yard Machines wally-world push mowers. 4 years old. This started last spring.

When I prime and pull start, it will start easily. But will only run for 30 seconds or so. Here's a quick vid.
http://s12.photobucket.com/albums/a243/computervitals/Misc/?action=view&current=05271913.mp4

Anyways, it seems like it's running out of fuel, After it dies, you'll have to prime and pull start 20-40 times before it will start. Then it will run a little longer.
Once this is done like 3-4 times, it will stay running but seems like it lacks power.

I've rebuilt the carb. A local small engine shop wouldn't give me a lot of info, but told me to start the mower and let it die, Pinch the fuel line and start to take the bowl of the carb off, If the bowl is empty then it's a fuel delivery problem.
I did this and the fuel bowl is full of fuel.

Any ideas?

 

[halfmoa]

Re: Any Lawn mower techs?

You say you've rebuilt the carb. Are you sure you cleared all the fuel passages? Screens clear? Hoses clear? Nothing in tank blocking fuel flow? Fuel filter new? (if it exists..probably not) Float installed correctly after bowl reinstalled? Jet clear? (the jet is in the fuel bowl screw if it's the engine I think it is) Good spark? Nothing blocking causing arcing between the kill switch contact and block/bracket? Fresh fuel? (probably should have listed that first) Proper oil level? Clean air filter? Crankshaft brake completely disengauging? Head gasket leaking? Compression OK? Pull the head and clean the valves of carbon?

That's about everything I can think of.

 

[rbh]

Re: Any Lawn mower techs?

YUP, sounds like your leaking air in between the carb and head.
once you get it going before it stalls hit the gasket area with wd-40 and see if the idle picks up.

(once the head expands from the heat it runs sluggishly, right??)

 

[dolluper]

Re: Any Lawn mower techs?

Get your carb rebuild info here
http://outdoorpowerinfo.com/repairs/

 

[CharlieB]

Re: Any Lawn mower techs?

Compression test may give an idea, but a cyl leak down test would be a better test to show if either valve is leaking.

It has a 'sound' that I suspect is a leaky intake valve.

I've seen a number of mowers from WW that erode the intake valve and/or seat enough they loose all valve clearance and begin to leak off compression, remove the valve and take a few thou off the stem until you get about .010 cold clearance and they run fine again for years.

 

[nwcove]

Re: Any Lawn mower techs?

if the float bowl gasket on that engine leaks , it will act up as you are describing.

 

[Bob_VT]

Re: Any Lawn mower techs?

Been there done that with the same mower.....

Clean the carb and pay VERY special attention to the fuel bowl. It must be sparkly clean. Very common problem and the slightest dirt in the fuel bowl gets those mower's to act that way

 

[rivermouse]

Re: Any Lawn mower techs?

Been there done that with the same mower.....

Clean the carb and pay VERY special attention to the fuel bowl. It must be sparkly clean. Very common problem and the slightest dirt in the fuel bowl gets those mower's to act that way

I agree 100%

 

[Big Bubba]

Re: Any Lawn mower techs?

I agree with Bob-VT that the carb needs to be really sparkling clean. Yeah, I bought a 1989 Troybuilt Tiller, with a 4 horsepower Tecumseh motor and it would only run with the choke fully applied and once you took it off the choke it would immediately die on me but I knew it was the carb on it becuase of the knowledge I have learned right here on IBoats. Yeap, bought a $11.00 Tecumseh carb rebuild kit and a gallon can with basket of the gunk parts cleaner from Advance auto Parts and let it soak for 24 hours and put it all back together after blowing out all jets with spray carb cleaner and compressed air and had to do some minor tweaking on my carb and she purrs like a kitten and we got our garden plowed and planted over "Good Friday" weekend this year. My carb was really gummed up inside it look like it had red mud inside of it.

 

[fat fanny]

Re: Any Lawn mower techs?

I would bet it's the primmer bulb it most likely is not holding vaccum. Most late model carbs include the bulb in thier re-build kits. Good luck

 

[dolluper]

Re: Any Lawn mower techs?

Primer bulb pin-hole sounds about right with all the mutiable pushes

 

[Big Bubba]

Re: Any Lawn mower techs?

Yeap, I agree with that too being a primer bulb not holding pressure because of a pin hole leak, been there done that.

 

[BuzzStPoint]

Re: Any Lawn mower techs?

I'm going to check it out tomorrow.. As for the primer bulb.. new one installed Friday..
No change. Does the same thing.

 

[markheck1]

Re: Any Lawn mower techs?

let me guess....it ran fine last year , but when you got it out this year, it was running funny.
We see this in the shop ALL the time
You have a plugged passage somewhere inside the carburetor. Have you checked the price of a new carb, some of them are pretty cheap. Otherwise, you'll need a good carb dip, or ultrasonic cleaning. But sometimes, that just doesn't work and you need a new carb.
Todays gas it Horrible

 

[robert graham]

Re: Any Lawn mower techs?

That little white plastic fuel pick-up tube that runs from the carb down into the gas tank has a very fine screen in the end of it that can/will plug up with debris/trash/whatever....clean that little screen with carb cleaner, an old toothbrush and an air hose, and that might well fix your problem. I use Stabil in all my lawn equipment, but those little screens seem to plug up anyways. good Luck!

 

[dolluper]

Re: Any Lawn mower techs?

Robert I don't think he has that type of carb......would be nice if he told us model hp....and what he's already done

 

[Davem3]

Re: Any Lawn mower techs?

sorry to harp here, but this is why i use VP racing fuel in all my equipment here.

that includes, weed wacker,lawnmower, snow blower and my outboard motors............

now why should i do that at 12.00 a gallon, you ask.............

well, my FIL is a retired FF from shrewsbury, and it is all they use for their equipment, let's face it, if they used today's carptastic gas in the jaws of life..............

so, it is all i use, it has NO ethanol, and i have never rebuilt a carb, or flushed out a tank, ever...............

i personally LOVE it, and recommend it to everyone..................and NO i am a truck driver for polar beverages, not a slimeweasel ( errrrr salesman) for VP

 

[BuzzStPoint]

Re: Any Lawn mower techs?

Robert I don't think he has that type of carb......would be nice if he told us model hp....and what he's already done

Tecomseh engine
LV156XA 331010A
Carburator is a : Tecumseh 640339
It's a yard Machines MTD mower.

So far to date, I did a cleaning (no soak). The basic rebuild kit and primer bulb.
Removed fuel tank and fuel line. Flushed and cleaned.
Replaced vac hose on top of carb.

let me guess....it ran fine last year , but when you got it out this year, it was running funny.
We see this in the shop ALL the time
You have a plugged passage somewhere inside the carburetor. Have you checked the price of a new carb, some of them are pretty cheap. Otherwise, you'll need a good carb dip, or ultrasonic cleaning. But sometimes, that just doesn't work and you need a new carb.
Todays gas it Horrible

Yes, Mark. But the year before. It ran fine summer before then crappy the next.

As for a carb, about 60 bucks online, Trying to avoid that though. It's only a 120 dollar mower.

 

[CharlieB]

Re: Any Lawn mower techs?

Have you checked compression yet?

Open the throttle and turn the motor over slowly by hand while listening closely to the carb, can you hear any air/compression leaking back thru the carb?

These are very simple diagnostic tests that will tell you the condition of your motor.

Spending money on any parts, cleaning the carb, will not fix it if you have a mechanical problem.

 

[dolluper]

Re: Any Lawn mower techs?

Well a tecumseh....make sure both the holes [jets] on the float bowl nut are clear....the one close to the top of the threads is hard to see very small use a strand of copper wire to clean it out......its for idle The big one is the main jet........did you remove the main nozzle and clean with carb cleaner and replace the TWO orings????
Carb parts break down link
http://www.partstree.com/parts/?lc=tecumseh&mn=TEC-640339&dn=CASERIES_211640339-CA
Check my post 4 for repair info tecumuseh series 11...640217 same as yours close to bottom of page