The blown up engine picture thread.

Blew up my first ever engine today, so I figured maybe it would be neat to have a thread dedicated to fragged engines. (Preferably lawn tractor engines of course). Post your destroyed mower engine pics and stories!

I was adjusting the carb on this rototiller which wasn't running quite right. I had just replaced the needle, seat, and float but I didn't take the carb off to clean it because it supposedly ran the previous season. (Working on it for someone else). Was running a little rough at idle and needed the choke half closed to run. I richened the low speed was out and then ran the high speed out some too just messing with it to see if it would clear out. I figured I would probably have to clean the carb out. Decided to set the high speed jet back where it belongs, so I held the throttle wide open and then ran the jet in to lean it out until it picked the rpm up which is what I normally do to get them close. Only takes a couple seconds, then you let off the throttle.

As soon as I got the mixture close and it revved up, there was a 'pling', something flew out of the engine on the other side, and it got a lot quieter.... The only sound was the crank still whirring around until it finally slowed to a stop. At first I thought something came off the flywheel or some piece of tin got caught in it somehow. I looked over and recognized a piece of connecting rod laying on the ground. I finally blew something up! So now I have to get a replacement engine out of my stock pile, but I have some cool broken parts to put somewhere.

This is where the parts ended up just after it happened. The only piece of con rod to make it out of the block lays near the bottom of the picture. All the other small pieces on the ground are chunks of the block. One by the gas can, another by the piece of rod. You can see the oil speckled on the ground.


Hole in the block. Rod broke completely off the crank. Piston stayed up in cylinder, held by ring tension.


Just visible is the top half of the rod still attached to the piston.


Everything off the ground outside the engine.


The rest of the rod was laying in the crank case.


I think this ding in the rod (being pretty wide and smooth) must be where the crank hit it. I think the bottom of the rod must have broken first, then the crank came around again, whipping it out through the block.


Piston is relatively undamaged except for a ding in the skirt where the rod made contact, seen on the left. You could probably clean up the crank and reuse that piston if you wanted. The main issue being the huge hole in the block. Not worth the effort really. Planning on replacing it with a 3.5hp briggs flat head.

What kind of engine was it? Teccy?

^^ Its a Tec.

I have 2 blowed up Tecs off of troybuilt tillers.
My guess they arnt too tolerant of not having oil where it should be.

Yeah Tecumseh, 4hp. I've mostly messed with briggs stuff, but I did have a tecumseh 3hp engine I ran pretty hard without any issues. Lack of oil wasn't the problem in this case because the bearings were ok. I suspect a bad casting that happened to hold up under normal use until now. Unless the governor wan't right and it's been running too high during use for a long time and it finally got stretched. It didn't take much to blow this one, I think with some more hours it might have failed anyway.

Sorry its not a mower, but its my ford 5.0 from my mustang. P/O blew it, ran it out of oil and fried the bearings then the crank snapped.

That's not good. Make much noise?

I'm sure it did, but it blew up before I got it. The P/O said "I was just driving down the road and it suddenly the steering wouldn't work and it started slowing down" (Clueless female P/O.) when it stopped it threw the serpentine belt off, and her boyfriend thought that the belt had just broken, didn't notice the crank pulley was at a 15 degree angle off from the rest of the pulleys... After the new belt was installed it still wouldn't crank lol.