Briggs Kaput

[toolmaster]

Hi - I'm new to the forum. Like many before me...I had a problem and looked on the internet to see if there was a forum that could help. Thats you guys!

I was happily mowing my lawn today when I had a catastrophic engine failure. I knew immediately that the engine was toast, but I pulled it apart to see what happened anyways. It had plenty of oil, and was not seized. The last two pictures show the cylinder can move, and the bore of the cylinder is quite smooth. This engine is off a 2006 craftsman lt3000 that gets maybe 100 hours of use per year. It's clearly out of warranty, but was not abused and was a young motor.

Any guesses as to what might have happened? Manufacturers defect or user error?

 

[isacguy]

Sometimes the connecting rod can get a small film of oil varnish that will keep oil from circulating along the rod bearings, it is rare but it is possible. It just happened to a friend of mine who had a perfectly maintained Audi. The rod is starved for oil, heats up, and BLAM it breaks. If it was serviced as you say, then it is just a freak accident that could not have been prevented. If the rod didn't blow a hole in the block and you feel like trying, you could attempt to rebuild it, but that is a lot of work, and it may not even be worth the trouble compared to getting a new engine.

 

[toolmaster]

There is a large part of the case that broke off - you can see it in the first and second pictures. Also, one of the arms that holds the counter balance has a nice crack in it. I think this engine is toast. I'm just hoping that if it doesn't look to be my fault, briggs might be in a good mood and send me a replacement. I like your theory of oil starvation on the rod bearings.

Sometimes the connecting rod can get a small film of oil varnish that will keep oil from circulating along the rod bearings, it is rare but it is possible. It just happened to a friend of mine who had a perfectly maintained Audi. The rod is starved for oil, heats up, and BLAM it breaks. If it was serviced as you say, then it is just a freak accident that could not have been prevented. If the rod didn't blow a hole in the block and you feel like trying, you could attempt to rebuild it, but that is a lot of work, and it may not even be worth the trouble compared to getting a new engine.

 

[KennyV]

Welcome to the Forum toolmaster...
From what I have seen with rod caps separating for no apparent reason... I would suspect an over-rev at some time in it's recent life...
Not saying you did it but has anyone else had the opportunity to wing it up... Too many RPM's will stretch things and set them up to fail... :smile:KennyV

 

[toolmaster]

Not sure how you over rev a lawn tractor - The motor has one speed. On. That is, until today.

Welcome to the Forum toolmaster...
From what I have seen with rod caps separating for no apparent reason... I would suspect an over-rev at some time in it's recent life...
Not saying you did it but has anyone else had the opportunity to wing it up... Too many RPM's will stretch things and set them up to fail... :smile:KennyV

 

[KennyV]

Not sure how you over rev a lawn tractor - The motor has one speed. On. That is, until today.

It's easy... reach down and hold the throttle open... deliberately or accidentally ... the governor normally regulates it but if the linkage is held ... The engine will go right up to Boom... :smile:KennyV

 

[toolmaster]

Nope - I'm the original owner. I only used it to mow my lawn - not play games.

It's easy... reach down and hold the throttle open... deliberately or accidentally ... the governor normally regulates it but if the linkage is held ... The engine will go right up to Boom... :smile:KennyV

 

[KennyV]

I only used it to mow my lawn - not play games.

You don't necessarily have to be playing games to have an engine over stress itself...
I would not expect a defect to last 400 to 500 hours... with a bit closer examination you may eventually figure out what failed first. But just going by what you have posted, I agree it's broke beyond a reasonable repair... replace it with a new or good used engine... :smile:KennyV

 

[CajunCub]

Sorry to hear that your season started out with a bang. Well, you'll get a new mower out of it.:thumbsup: Post here when you get it. Good Luck!

 

[jeff]

Check with jackssmallengine.com they recently had a sale on replacement engines.