Repairs Cub Cadet Piston Ring(s) Broken ??

CalgaryPT

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Hi guys -

The other day my neighbour wheeled her Cub Cadet OHV 173cc into my garage with a sad look on her face and said it won't start. This was the last mow for the season and the machine always started and ran fine on the first or second pull up to this point.

When I pulled the starter cord, the cord would come to an abrupt stop after 6 inches or so. With a little coaxing and gentler pulling I could eventually get it to a point where I could get a full pull on the cord and it would start. However, when it did start it blew a lot of smoke and spits oil from the exhaust (it never did this before).

I'm thinking this is a broken piston ring. Does this sound right?

(I let her use my 25 year old Briggs I rebuilt last winter to get her through the final mow of the season, but I think I have a project on my hands with her mower for the winter!)

Thoughts???
 

ILENGINE

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If the engine was stored with the spark plug facing slightly down hill, oil could seep past the rings into the cylinder. Check make sure the oil level is at the correct level and see what happens. May just be nothing.
 

CalgaryPT

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Hummm......engine has always been on flat surface. The pull cord "seizes" about 1/4 way through when you try to start it. Then when you more gently coax the cord to about its 3/4 length--it feels normal and you can give it a quick tug to start it, but it blow smoke and spilts oil.
 

ILENGINE

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Could the mower of been tipped to check underneath and allowed oil to enter the breather system where it was drawn into the intake. The oil level in the sump normally won't be high enough to allow the oil to enter the cylinder unless overfilled or tipped. Even with bad rings.
 

dfbroxy

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Im assuming this is a OHV engine. With the motor running, pull the dipstick. If there is blowby(smoke or oil) then its likely a blown head gasket or the rings like you said.
 

CalgaryPT

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Im assuming this is a OHV engine. With the motor running, pull the dipstick. If there is blowby(smoke or oil) then its likely a blown head gasket or the rings like you said.

Thanks dfbroxy. I check this too.
 

Scrubcadet10

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Im assuming this is a OHV engine. With the motor running, pull the dipstick. If there is blowby(smoke or oil) then its likely a blown head gasket or the rings like you said.

Well, actually a little smoke is normal. But that's after running awhile. another way to do it, take the dipstick cap off, while its running, and if the cap bounces around up and down, that means air (compression) is getting into the crankcase.
 

Scrubcadet10

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And also, I'M NOT SURE, But when you talk about the pull rope being sticky, when you pull it. That *MIGHT* be the rings gouging the cylinder wall, it maybe or maybe not.....
But yes, more than likely the rings are wore not broken, BUT it sounds to me like this happened all the sudden, so i would say one of the rings failed.
 

CalgaryPT

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All great advice. And yes it is an OHV. I'll get access to the mower in a few weeks when my neighbour returns from vacation and I can play with it.

Thanks everyone. I will report back with my findings.
 
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