So my lawnmower was a hand-me-down and basically 12 years old. So last season, I bought a new lawnmower...6.5HP Craftsman from Sears...it's a beast.

Anyway, I changed my oil at the beginning of this season and I put 20oz of like 2-year old 30HD oil in it that had been sitting in the un-opened bottle in my garage (unheated garage).

I cut the grass, front and rear -- basically ran it for close to an hour. Then today I went to cut the grass...got through the front lawn like normal, then as soon as I went to the back, I got one crossing done and it started sputtering. I figured I was out of gas, but the gas tank is still full.

I checked the oil level and it is fine...Do you think the old oil could have ruined the motor? That's ridiculous...I changed the oil in my old lawnmower with automotive 10w-30 most of the time...I would sometimes not change it at all for the year, and the only problem I had with it was the pull-start cable broke off and I didn't feel like fixing that.

Do they make lawnmowers like crap these days or do you think I messed something up? I mean if the spark plug was bad, wouldn't it just not start...what are the chances that it would go bad right when you're in the middle of cutting the grass when it's all warmed up and everything? I could definitely see the motor seizing up though at this point because it was hot...and the recent oil change has me worried.

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First step??? I'm thinking go get a spark plug tomorrow morning and try again...if that doesn't work, I'm out of ideas other than change the oil again lol.

 

Just change your plug and go from there. I dont see how changing the oil again is going to help anything but then again, what do I know...

 

lol that's what I was thinking. I'm open to suggestions...keep them coming, I'll check in the morning. Thanks.

 

The chances are better for a plug to foul when it's hot. Thats when the plug is the softest.

If it was the oil then I'd say it would seize up not sputter. Sputter is a mis fire wether it be from bad plug, or bad magneto, or bad air/fuel mixture. One reason or another ignition is not possiable.

 

Good points PSS.

I stopped at the parts store today and got a spark plug and figured I'd just change the oil again since I was there. I figure the other oil I put in was probably good, but it would be like a flush, completely new oil.

It's a Craftsman 6.5HP motor. It had a champion plug in there, the gap was at .026. I crossed the part number over and came up with an Autolite 458. The gap on that was already set at .026, so I'm assuming that was where it should be (having lost the owner's manual of course).

Put it in, changed the oil...runs like new The back yard is cut.

 

My dad just bought a new walk behind for his place. Its also the 6.5 Craftsman but has the electric start as well as the pull start. I like my Craftsman 16.5hp 42" cut. Still not big enough though. I only change the oil, filter, plug once a year. Which reminds me a lady down the street asked me to tune up her Craftsman rider. Its like 5 years old and the oil has never been changed.

 

Sounds like a plug or some 'goop' in the bottom of the gas tank that may have been brought into the fuel system (carb).

RP

 

Now bring it here and do the 1.5 acres left to mow at mine.
Carb went bad on my rider half way through so have to wait to get a rebuild kit.
Technically carb has been bad for a while I've had to run it choked for a while, but now after it has warmed up, it wont stay running no matter where the choke is.

So likely tomarrow, if I remember too, then after work I will try to stop and get a rebuild kit and some carb cleaner and hopefully I'll be able to fix it.

10 year old Crapsman with 18hp, twin cylinder, OHV, B&S. I/C engine and a 42" deck.

I may just retire it, it's a hunk of junk. Last summe ri spent enough money to buy atleast one and maybe 2 more just like it just trying to keep it going. But it was probably an average of $30 each week in repairs. It's been nothing but a headache and troble since literally day 1.

 

lol...we used to have one like that up at our camp. It was probably 1950'ish and something would go wrong just about every other weekend. We ended up seeing a newer one at a yard sale driving by about 3 years ago, picked it up and it's run fine ever since with just general maintenance.

 

Good to hear you got it running again. The last, and I mean that LAST Cratsman mower I bought, at the start of the 2nd season, and I bought it in like August the year prior, when I started it up, oil blew out from all around the engine. I made Sears fix it, then I sold it, got a Toro. Best one I've ever owned. Next to the John Deere my dad had when I was a youngster that is.