Is my push mower dead? (Plus rant)

[N80]

I've got a 10 year old push mower. Its a 6.5 hp B&S 'Inteck' engine that has 2 valves. (Valves on a lawn mower engine! ...rant to follow). It has seen light duty at best.

Anyway, my daughter was mowing the front yard and noticed grass was building up under the mower deck. (Grass was long, maybe too wet.) So she turned it off and lifted the mower deck and cleared the grass away. Then it would not start. You couldn't even get the pull chord to pull. I assumed it had seized but it had not. I could hand turn the blade some, but with difficulty.

So, I take it in the garage and start taking it apart. (I used to could fix almost any basic lawnmower....of course this one is hardly basic.) First thing I notice is that there is oil in the air filter and up in the air intake and carb. Oil also coming from exhaust. Pull spark plug and there is oil all over it but now pull starter is free. Everything rotates fine and smoothly but each time the piston comes up oil is glopping out the spark plug hole.

There are no oil leak anywhere else. Everything spins properly. No grinding of sound of broken parts.

Put it all back together but it won't crank. With each tug oil and gas come out the exhaust.

Is it dead?

Rant? Suffice it to say that I have two other ancient lawn mowers with basic B&S engines with less horsepower. They sit outside and rarely get used. But, they crank every time and put a better cut on the grass. Seems like more money for the new ones gets you less reliability, just as hard to start and if truth be told, worse cut quality.

 

[MikeD74T]

N80, Glad to hear that your daughter did NOT loose a hand in this event. Cleaning the bottom of a lawn mower without understanding the machine is very dangerous. Under unusual circumstances a mower can start by moving the blade as little as a couple inches.
On to your rant.... lawn mowers have been powered by 4 stroke engines for several decades now. 4 stroke engines all have valves -that's not new. What happened here is when the mower was upside down or on edge the crankcase oil flowed past the rings and/or through the crankcase vent into the carburator & cylinder. Being non-compressable the oil preventd the piston from traveling full stroke. What you need to do is remove the spark plug, clean it with a good solvent (acteone, carb cleaner, etc), pull the rope until gas & opil stop coming out, replace the spark plug, & it should start. OH, and check the oil level before you try to start. MikeD74T

 

[Chuck52]

It seems I have to buy a new push mower every few years. I always buy the cheapest I can find because I'm mainly just using it to trim where I can't get with the rider, but I also use it like a brush hog. I cut high weeds and in areas where I know I'm going to drag on ruts and stuff. So, I buy the bottom of the line from WalMart or one of the box stores. Now that I think of it, I shouldn't really say "always", because I've had the same mower now for at least 10 years, and the one before that also lasted 10 years. The current one is now almost dead, but since it probably still has the original oil in it I guess I can't complain.

The cheap ones have cheap, simple engines. I did replace the carb on the current one a couple years ago, using the carb off one a friend gave me. Looks like I may have to pay over $100 for my new one this year....first time for that!

Chuck

 

[oldnslo]

When you tip your mower tip it away from the spark plug and carburetor. Tipping it towards the plug can fill the cylinder with oil like Mike D said.

remove the plug and clean it, regap it it may have been damaged by the oil. It will probably smoke at start up but should run fine.

Roy

 

[N80]

Mike, she understands safety precautions with the machine. It was off and the safety release bar was released. It cannot start this way. Even so, I'd already warned her never to turn the blade on one without detaching the spark plug wire.

I had already done everything you've mentioned and no go. Will try again later. It might even be flooded. However, I've tilted this machine up and even over dozens if not hundreds of times and have never had oil in the chamber like this. But, I did not see what she actually did so no telling.

I'm hoping you are right, and you probably are, but even after all the oil has run out of the spark plug hole and the spark plug is clean, it is still pumping lots of oil out the exhaust with each stroke.

As for the valves I meant overhead valves. This thing has two valves on the one cylinder. With push rods, rocker arms, etc etc. Seem highly unnecessary to me.

Chuck, my two old ones are over 20 years old and run and cut better than my 'new' one that is now broken. I doubt they've ever had an oil change. (They were given to me.)

My next one will be a $120, non mulching, non self propelled, non DOHV model. Unless B&S has moved to China I'd wager that it will last longer than me.

Of course the real issue here probably isn't old vs new, complicated vs simple or even have anything to do with any known mechanical solution. The real moral of the story is not to let your 16 year old girls use machinery. (Although she has become fairly proficient on my Kubota tractor. Gulp.)

Heading out the door now to go turkey hunting...with the same 16 year old....will check back here tomorrow and try the steps you guys recommended again.

Thanks.

 

[jinman]

George, all that oil in the intake may have contaminated the carburetor to the point that it will have to be flushed out. You can also expect a lot of oil in the intake and exhaust ports that may get sucked into the cylinder and foul the plug. A thorough cleaning of the cylinder and carburetor intake is a minimum requirement. I would recommend using a carburetor cleaner like Berryman B12. Also be prepared to have your mower smoke like crazy when you get it first started.:shocked: Your muffler is probably loaded with oil.

You can turn a mower every direction but one to work on it. If your daughter had just turned the mower up on its opposite side, this thread would probably never have happened. Unfortunately, she picked the right procedure in the wrong direction. I hope she doesn't feel badly. It's a mistake anyone could make.

 

[Yankee]

The best mower I ever had in some respects was a cheapie where all the accessories had failed over time and I didn't bother to replace them. That included the pull start, throttle, drive, even the operator presence controls. In the end it was an engine, deck, and handle. I had to wind a rope manually to start it, set the engine speed at the engine, and ground it out to kill it. Ran for YEARS with an occasional oil change.

Go to say that I detest Briggs engines, though. The initials aren't BS for nothing.

 

[2manyrocks]

It seems I have to buy a new push mower every few years. I always buy the cheapest I can find .....The current one is now almost dead, but since it probably still has the original oil in it I guess I can't complain. Chuck

Changing the oil and air filter every so often does wonders for small air cooled engines.

Now there are some folks who could kill a Briggs quicker than Wyatt Earp. My aunt killed more mowers, and I have no idea how she did them in so quickly.

 

[Egon]

Last mower with a Briggs and Stratton engine I had Lasted 27 years.:thumbsup:
Finally there wasn't enough compression to start it.

Next mower with Tecumseh engine lasted two years till I did the same as N80's daughter.

Present lawn mower has a Hondo engine.

 

[SensibleNick]

My BS powered machine does the same trick every now and then when I tip it over on the wrong side. I usually notice when the oil starts to hiss as it enters the exhaust.

I've never managed to get enough oil into the cylinder to give it hydraulic lock though, and I've always managed to start it and watch with a stupid grin on my face as the resultant cloud of smoke drifts off into the distance.

I agree with everyone else: It ain't broke, it's just pretending that it's a hydraulic cylinder.