169 threw the rod...

[kalebevans]

My dad was using my 169 to mow his lawn, and it decided it was done. The k341 threw a rod, so it's rebuild time. I'm a lucky guy; the pieces fell into the pan without going through the block or even chipping the cylinder. Everything looks pretty good, except there's a fair bit of galling on the crankshaft. I'll take it and the block in and have them checked out and properly measured to see if it needs to be bored over or just cleaned up a little. The balance gears do have a fair bit of play to them, so they'll probably come out. Here's a picture of the pan just for fun.

[MARK (LI)]

I hate it when that happens

[ol'George]

I'd say ya done blowed it up junebug

[kalebevans]

Yep. What seems odd to me is that it had been running at WOT and was full of oil. He throttled down, removed the load, and it was idling for a moment before it went. It looks from the galling like it didn't have oil and heated until it seized on the crank, making the rod snap. This is my first blown engine, though, and I'm no mechanic.

[finsruskw]

Had he been mowing tilted on a steep side ditch or hill??

[Cub Cadet 123]

Originally Posted by kalebevans

Yep. What seems odd to me is that it had been running at WOT and was full of oil. He throttled down, removed the load, and it was idling for a moment before it went. It looks from the galling like it didn't have oil and heated until it seized on the crank, making the rod snap. This is my first blown engine, though, and I'm no mechanic.

Sorry to hear the bad news, but that idle might have prevented damages being worse to the block. In all of the bad case scenarios, it seems like you may have gotten the best luck of them, judging by your pictures and what you wrote.

Cub Cadet 123

[Bob95065]

About 1988 I was driving a neighbor's 122 on a level, grass field when the engine shut down. I turned the key to find the engine turning over very fast. I knew something went wrong. We towed it back with their 1000 and I started tearing the 122 engine down. I found the same thing you did - the rod shattered like glass.

The bore and crank looked great and measured in spec. I put a new rod, piston and rings in it. The engine was still running great the last time I saw it in the late 1990s.

[dvogtvpe]

weak link in a K series is the rod, its a poor design and along with a cast crank that tends to wear out of round its a combination looking for a divorce

[kalebevans]

Originally Posted by finsruskw

Had he been mowing tilted on a steep side ditch or hill??

No, he was on pretty flat ground. There's some slope elsewhere on the yard, but it's nearly all done headed straight up and down; nearly no side slope.

[Mike McKown]

Originally Posted by Bob95065

About 1988 I was driving a neighbor's 122 on a level, grass field when the engine shut down. I turned the key to find the engine turning over very fast. I knew something went wrong. We towed it back with their 1000 and I started tearing the 122 engine down. I found the same thing you did - the rod shattered like glass.

The bore and crank looked great and measured in spec. I put a new rod, piston and rings in it. The engine was still running great the last time I saw it in the late 1990s.

I bought a 129 from a dealer about twenty years ago. It hadn't ever spent a single night outdoors. Had a replacement (black) engine. Broken rod. Original owner traded it in.

I didn't bother to mike the crank because it looked like new. Put a new rod in and ready to go. Still have the tractor and still runs fine. Must have been a weak part?