Question about Yard Machines 11A54MC006 21Inch 139cc MTD OHV Gas Powered Side Discharge

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Yard macine model 139cc will not start. Has gas and oil... where is the spark plug located on the lawn mower? I would like to replace it.

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The spark plug is at the end of the thick black wire in the middle of the front of the engine or looking at the mower from the front, it is to the left of center. Make sure you set the spark plug gap before installing it new. The gap is probably around .030". They have tools for doing this at the auto parts store. Sometimes and older plug can be cleaned with a stiff wire brush and some solvent and gapped properly and continue to work well.

Posted on May 28, 2011


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Overfill oil

Sounds like the engine is tired. Blue smoke is oil burning. Hard starting is oil on the spark plugs and/or low compression. This also can be due to someone adding too much oil.
Sometimes, the carburetor Needle valve hangs u pa bit and the Crank case oil gets mixed with gas so now the oil level is high. Too much oil in a motor is bad too, that would cause theblue smoke too.

Jul 20, 2013 | Yard Machines 11A08MB006 22Inch 139cc MTD...

1 Answer

1 year old 139 cc will not start. it will go for a minute but very low idle

was gas left in it for more than 30days?if so the carb might need a cleaning

May 12, 2012 | Yard Machines 11A54MC006 21Inch 139cc MTD...

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Where is oil drain plug

Hi ahoff50677...
As strange as it seems you may not have one.
On some of the newer mower models they do not have drains.
You will have to tip it on its side to drain the oil out.

If you do have a drain it will be located on the bottom of the engine, under the mower housing, look for a square plug, or maybe a allen socket plug.
Please take time to rate me

Jul 05, 2011 | Yard Machines 11A54MC006 21Inch 139cc MTD...

1 Answer

It just quit running...sounds like it's trying to start...It has gas and oil and the filer is clean....

Check for spark, try pulling the wire and hold it near the engine while trying to start it, look for a spark to jump. If no spark replace the wire or the ignition coil. If you get spark try replacing the spark plug. if you get spark you should also pull the spark plug and see if the end of the plug looks wet if its not wet you aren't getting fuel and I can make some other recommendations.

Jun 08, 2011 | Yard Machines 11A54MC006 21Inch 139cc MTD...

1 Answer

The mower starts runs very weak , for a few minutes then completely stops...oil is good,gas tank full with new , fresh gasoline

i would try first of all replace the fuel filter and check clean or replace your air filter. Personally I think it is going to be the fuel filter that is clogging and causing this. And for little cost replace the plug and make sure it is gaped right.

May 15, 2011 | Yard Machines 11A54MC006 21Inch 139cc MTD...

1 Answer

Hi, after deposited it for the winter, the cord

I have thought about this problem for a while now. It came to me that what you are experiencing is the aftermath of the WAY you my have stored your machine. If you stored it on it's side or on it's end ,this may have allowed the engine oil to leak into the cylinder . This causes the piston to be blocked by the engine oil.
First to see if this is so, remove your spark plug, if oil starts coming out tip the machine to allow the oil to get out of the engine. You can probably clean the spark plug with carburator cleaner, or just replace with a new one. Replace plug, fresh gas, and start. Your mower will smoke for a while ,but will then start to run clear. I hope your problem will be solved. GOOD LUCK.

May 13, 2011 | Yard Machines 11A54MC006 21Inch 139cc MTD...

1 Answer

String will not pull

This could be hydraulic lock. Remove spark plug and try pulling it over. If this is the problem you will see gas or oil being discharged through the spark plug hole. If this is not the case make sure your safety brake (the little handle you have to depress on handle bar) is working properly. If so you will have to remove starter shroud and look for problems there.

Oct 04, 2010 | Yard Machines 11A08MB006 22Inch 139cc MTD...

1 Answer

My murray push lawn mower won't start

did it die right after a refueling? You might have water in your fuel can.
Which now is probably in your mower.

Drain out all the fuel *(remove the carb bowl too) Get some fresh gas *(dump your can of fuel out into a secondary container so you can look for water in it. If it has water on the should dispose of it wherever you dispose of your mowers waste oil.

You should be sure you have spark. Which means you need to remove the spark plug from the head and with the boot still attached dangle it on the metal head and give it a pull and look for sparks. If you have no spark you might need a new plug or coil. Thats really all you can do for weak or no spark. Be sure the plug is clean and free of oil/gas contamination as that may have fouled the plug.

Good luck and be careful!

Jul 13, 2010 | Yard Machines 11A54MC006 21Inch 139cc MTD...

1 Answer

Where to find the spark pug on my 21inch 139cc mtd ohv lawn mower

It should be under a rubber boot between the valve cover *(stamped OHV or OHC) and the muffler.

Good luck and be careful. Dont pull that boot when the engine is hot!

Jul 07, 2010 | Yard Machines 11A54MC006 21Inch 139cc MTD...

1 Answer

Lawnmower won't start

Remove the bowl from the carb. and blow it out with air.

May 07, 2010 | Mtd 22" Yard Machine Push Mower

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