Question about Mtd Yard - Man 160cc, 21" Self - Propelled Lawn Mower

5 Answers

Lawn Mower smoking/mufler leaking oil

I think my son ran it when the damp grass had clogged up outlet. It started smoking and tied, I looked and seemd like out leaking out the muffler. Let site for a while and cranked up and the smoke was bluish and was intense. Started leaking again. Someone please help. Briggs and stratton motor

Posted by on

  • dsgb51888 Jul 23, 2009

    It wasn't upside down but tried this anyways. Worked for a minute then it began to smoke agin and leave oil(?) oout of the muffler(front left or motor)



5 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

I have a yardman lawn mower that is two years old. It is now blowing oil out the exhaust and also blue smoke. Any idea what is wrong?

Posted on Apr 23, 2010

  • Level 1:

    An expert who has achieved level 1.


    An expert that got 5 achievements.


    An expert whose answer got voted for 20 times.


    An expert who has answered 20 questions.

  • Contributor
  • 32 Answers

Was it turned upside to unclog it. if so check to make sure proper oil level and start it up and the smoke should clear in a minute or two

Posted on Jul 23, 2009

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert who has written 50 answers of more than 400 characters.


    An expert whose answer got voted for 20 times.

  • Expert
  • 168 Answers

Suggested answer number 3 is the most likely problem. If you decide to turn any vertical engine on a mower I suggest you never tilt it to clean it with the airfilter box pointing down towards the ground. Always remove spark plug before doing this as a safety thing. The best way to clean a laen mower is to turn on the garden hose and simply spray the water under the shroud. That will cause the water to agitate in under and blow excess grass out the blower chute.Remove the bag if its a rear or side bagger and stand back.

Posted on Dec 01, 2014

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 8 Answers

Check your oil level to start with. If overfilled ,drain some out. If not over filled the mower could have been turned on its side causing oil to get in the crankcase breather and then forced into the air filter box . Check your air filter if its full of oil remove it and start the mower up and it will quit smoking in a few minutes,install new air filter n start mowing

Posted on Nov 29, 2014

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 2 Answers

Mine is doing the same thing. It will stop...
...when all the oil has shot out and is all over the yard.

Posted on Jul 07, 2012

1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Kohler engine oil leak

Could have blown a seal however before checking for that I would check the drain plug and filter seating if you changed the filter. Make sure the drain plug is not cross threaded. You can run a little low but should never over fill. Hope this will help. Most of the time if over filled you will get some smoke as well.

Apr 25, 2014 | Garden


Top 10 Lawn Mower Problems and solutions 10: My mower clumps the grass up when...

Top 10 Lawn Mower Problems and solutions
10: My mower clumps the grass up when cutting
This is a common problem especially in the spring time. Wet grass builds up under a deck more so when mulching rather than bagging. Mulching grass is great for the lawn but if the grass is wet you are not mulching but rotting the grass. It is recommended to have your blade sharpened and balanced at least once per month or sooner if your lawn has a hardy grass type.
Local lawn shops like offer replacement blades at half price to make it simple. Some shops even offer a trade program so you can have a sharp blade the same day.
Remember mulch when grass is dry and bag grass that is too wet. Never use a dull blade! It is bad for the lawn.

9: Electric start will not turn the engine over
With many brands offering electric start at a low cost to consumers this problem is more and more frequent. One reason electric start cost less now is because of the cost of battery technology. Less expensive batteries make for lower cost but the old adage "you get what you pay for" still comes into play. Many brands have opted for a battery that if maintained will last for about 3 years. However maintaining your lawnmower battery can be as complicated as: trickle charging every 30 days for 24-48 hours then once a season for 48-72 hours. If this is not the track record for your battery It is recommended that you take your battery in to a local shop again like Arco Lawn to have the battery "load tested"
If the battery passes the load test split your system in half by checking to see if the engine will turn over with a direct jump to the starter. MAKE SURE YOU TAKE SAFETY PRECAUTIONS! (like removing the spark plug wire and not having any limbs in the way of moving components).If the engine turns over you know the problem lies between the battery and starter. The common problems with the electric start wiring between the battery and starter include: fuses, switches and corroded wires.
maintaining your battery gives it longer life, troubleshoot by splitting the system and look for fuses switches and wires as culprits to an electric start problem.

8: Engine stopped running and won't restart
Many problems can occur with a small engine. Many times the simple things are overlooked when checking an engine. Start by checking the fuel followed by checking the oil. If either is out fill to the correct level. Oil running low is the number one reason that engines die out and won't restart (even after putting oil in the engine) This is do to heat build up in the engine and even component wear from heat. You may be surprised to see that your machine has no oil in it. Even if you had it to a local shop like... ahem ...ARCO LAWN for a tune up in the spring the average small engine will use 1/2 ounce per hour of running. This is not a well used engine that is now smoking blue-white smoke as it runs. Walk mower engines hold 18-20 ounces of oil in them. That means that within 20 hours of use the oil is low enough to do damage and at 40 hours the engine is completely out of oil. This does not take into account that as the air filter fills up with dirt and grass it causes the engine to consume more fuel and oil. If your machine has run low on oil it is recommended to take it to a local shop and have them perform a "leak down" test to tell you how bad the engine is damaged and if it is worth investing any more money into.
7: Rope won't pull out
Sometimes related to problem numbers 8 or 10 this can be a tricky one. If the oil is all gone many times the engine has welded itself together inside and needs to be repaired by a small engine shop. You can do this yourself with the right tools and a service manual. I recommend a parts lookup tool like this. You will need to write down the model numbers your machines engine to look it up.
The second most common reason for the engine locking up is grass packed under the deck because of a dull blade trying to mulch wet grass. Again I say it is bad to use a dull blade and don't mulch wet grass.
6: Engine is smoking
An engine that smokes can double as a mosquito killer until the EPA shows up to give you a big fine. Allot can be known about a mower by it's smoke. If you have a black smoke coming out of your mower it is from too much fuel. This problem can be caused by an air filter backed full of dirt or a fuel system that needs service.
If your engines smoke is blue-white and oily it means that oil is getting into your muffler. To find where the oil is coming from a great shop like ??? would use a leak down tester to see if the piston rings were stuck or worn letting oil bypass and get into the muffler but not until after they check the oil level and makeup. If the oil is overfilled and smells of gas then the engine will need a fuel system rebuild (kits are available to do this yourself).

Because of length this has been split into two parts. Please see Top 10 Lawn Mower Problems and Solutions (Part2)

Thank you Arco Lawn
Stihl Inc
and other referenced sites.


on Feb 22, 2011 | Garden

1 Answer

Oil coming out of air filter

Look for a crankcase ventilation tube or such, It may be covered with grass dust and stuff, is probably a sponge to keep dust out of the motor. Rinse it out, and make sure the airway is clear.

Nov 24, 2013 | Garden

1 Answer

My son may have ran over some damp grass with our Briggs and Stratton 500 series, 158 cc lawn mower and now it smokes and leaks oil out of the exhaust, how do I fix this?

if he tipped it on its side to clean the grass off the oil will burn off but check the oil level he just tipped it so the crank case drained into the cylinder also check the air filter that might have got oil soaked as well

Jul 09, 2012 | Garden

1 Answer

Briggs and stratton 6.5 started smoking so changed oil in hopes would help still smoking

sounds like it broke a ring to fix better to buy new moter not worth trying to fix

Jun 01, 2012 | Briggs & Stratton Lawn-Boy 10640 20-Inch...

1 Answer

I have a Poulan Pro - Briggs/Stratton 6.25. It ran really well and when i added oil (starting to think the wrong kind - sae 10w30 from gas station) it has continued to blow white smoke and then it sort of...

Yes,but do not drain it all off.It sounds like there may be too much oil in it.Drain some of the oil and start it again to see if that fixes the smoke.30 wt oil is ok to use in your mower.

Jun 18, 2011 | Poulan Pro 22inch 625 Series Briggs ...

1 Answer

Oil leak on riding Craftsman LT2000 (Kohler)

Fortunately, the engine oil doesn't go through any rubber hoses, so they are mouse-proof. The oil probably leaked out through an engine seal. Oil on the engine surfaces would smoke when it gets hot. Check your oil level and top it up if necessary, before you run the engine again. The engine can run fine even with a slow oil leak; you just have to watch the oil level from time to time. The leak could be easy to fix - by tightening up a few bolts -- or expensive.
The gas runs through rubber hoses, though. If mice ate through that, I think you would have smelled the gasoline, and the engine wouldn't run for more than a few seconds. But if you see a severed hose, you should replace it. Take it off and bring it to a mower shop or auto supply shop, and buy something the same diameter. Inexpensive.
Hope this helped! If so, please rate my answer, thanks!

Jun 07, 2010 | Craftsman 17.5 hp 42 in. Deck Lawn Tractor...

1 Answer

Billows of white smoke when Toro lawn mower runs

You overfilled the oil. If the mower runs, just go ahead and mow grass until it runs the oil out of the gas tank. Or you can empty the gas tank and fill with new gas. White smoke is not a serious problem. Only a hassle.

Jun 19, 2009 | Toro Lawn Mower With Toro Power Tools

Not finding what you are looking for?
Mtd Yard - Man 160cc, 21" Self - Propelled Lawn Mower Logo

3,217 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mtd Garden Experts

Jim Parker
Jim Parker

Level 3 Expert

1041 Answers

Tim Whalen

Level 3 Expert

3074 Answers

Phil Walker
Phil Walker

Level 3 Expert

608 Answers

Are you a Mtd Garden Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides