lawn mower oops

[FatNakedGuy]

My mensa.org smart 16yr old daughter just finished mowing the front lawn with our 6 months new $400 John Deer lawn mower.

She came in complaining that the mower wouldn't start after it got really hot. I asked about the oil level, then told her to let it cool down and try again. 1/2 hour later it still wasn't starting.

I went out to check it out and discovered:

a. the oil level 2x as high as it should be

b. gas in the oil, and air filter soaked with gas

c. a bottle of rotella synthetic 5-30wt oil next to the fuel can where she was mowing

I asked if smoke came out of the mower before it stopped and she said, not this time (not sure what that means). She said she was mowing along and the motor just quit, and was very hot and wouldn't start.

I'm assuming she used the rotella synthetic to fill up the mower and put more in than was supposed to be. I drained the oil (it was very thin and smelled of gas) the put the correct oil back in, checked the mower for spark (it is OK), and replaced the air filter. Still won't start. The pull of the starter cable seems too easy, and I can spin the blade around by hand easily.

So with that said, do you think this is a major oooops, or do you think it might be a seal in the engine somewhere that is bad and just needs replaced? I'm not up on mechanical stuff like this but the heat thing bothered me. Thought I'd ask all of you gurus out there. I'm going to google to see what I can learn as well.

Thank you!

 

[El Toro]

Don't know about your specific mower, but maybe the lawn mower gods will smile on you, and it will turn out to be sheared key. Sounds like maybe you've got a ring job ahead of you.

 

[madmike2]

You mean you're supposed to check the oil?

In the car, too? BTDT with "The Princess".

This isn't sounding good for you. Let's cross our fingers that it's something simpler like a stuck needle in the carb.

 

[FatNakedGuy]

Would a stuck needle in the carb put gas into the oil reservoir? Sure wish I had taken a mechanics class..

 

[madmike2]

Just like motorcycles. My old XS1100 had a bad vacuum fuel shut-off valve. If I didn't turn off the petcock it would flood one of the cylinders (through a carb where the needle didn't seat well) and the excess liquid would seep past the rings into the crankcase. Not a good combination if things go "boom".

My guess is, if she was using the mower and it "quit" that isn't the problem. You might try taking a compression test or simply placing your finger over the spark plug hole. If there's no compression....welllllll.....

 

[Geezer]

If you don't feel compression when you pull the start cord, then you probably have either a valve stuck open or stuck rings.

I don't know the shape of the profile on the rings of that motor, but it is possible for the overfilled oil to jam them in the grooves of the piston. This would explain gas in the oil, since fuel would easily get past the rings if they are stuck or broken. Lawnmower engines are pretty simple and I would pull the head off and see what it looks like from the top. If the valves look good and the piston looks good from the top, and goes up and down as you turn the crankshaft, then you'll have to pull the piston out and see if the rings are broken or stuck.

 

[charismaticmegafauna]

My mensa.org smart 16yr old daughter ... our 6 months new $400 John Deer lawn mower....wouldn't start after it got really hot. I asked about the oil level,

a. the oil level 2x as high as it should be

b. gas in the oil, and air filter soaked with gas

c. a bottle of rotella synthetic 5-30wt oil next to the fuel can where she was mowing

I asked if smoke came out ...and she said, not this time.

She said she was mowing along and the motor just quit, and was very hot and wouldn't start.

I'm assuming she used the rotella synthetic to fill up the mower and put more in than was supposed to be.

I drained the oil (it was very thin and smelled of gas) the put the correct oil back in, checked the mower for spark (it is OK), and replaced the air filter. Still won't start.

The pull of the starter cable seems too easy, and I can spin the blade around by hand easily.

Thank you!

Many similarities with a situation, years ago, at my local Yamaha dealer: young, bright, guy; new Yamaha XZ550 Vision; added oil up-to the top of the crankcase (filled it); quit running...

Broken pistons...

good luck, you're welcome

 

[dcarver]

I wonder if she added oil to the gas tank, and gas to the oil tank?

 

[Bustanut joker]

After reading through this twice I'm more apt to believe the needle stuck in the carb.. Gas then filled the crankcase to overfull.

How else would the filter become saturated?

Granted this doesn't solve your problem, but it does clear your daughter.

:jester:

 

[FatNakedGuy]

thanks all! I will work on it this weekend based on the awesome info provided! y'all rock!

 

[Tree Doc]

Stuck float likely. There's no other "mechanical" means for gas to get in the crankcase since your engine doesn't have a diaphragm actuated fuel pump. I'd also bet your sportin' a stuck ring, too. That's where your compression has gone to shit. Pretty easy fix if you're so inclined but I'd look at the cylinder walls after pulling that head. They could very well be scored and if that's the case, you're in for some real work or replacement. That may be a Kawasaki motor, J-D used Kawi's motors in mowers for years but that will depend on it's age.