Engine diagnosis needed

[ChickenPoop 15]

Hey all. I need some input. I recently purchased a wheel horse with a Kohler K341. I’ve been running it for a bit doing chores around the house. Not a whole lot though. I cleaned the carb when I got it. It was full of rust/flakes. It hasn’t performed to well under heavier loads especially when going up hill. It seemed it would surge a little bit but ran fine unloaded.

 

I finished mowing my small field yesterday when the engine suddenly sound different. I stopped to listen to it and a second later there was a loud clunk. I shut it down immediately. It took longer than normal to shut off completely. I pulled the dipstick and noticed some smoke coming out. There wasn’t hardly any oil on the stick and it was black.

 

I gave it a few minutes and turned the key. It turned and kept spinning freely. 
 

I understand I shouldn’t have trusted the person I bought it from to keep everything topped off and I should have checked myself. Lesson learned. 
 

I understand the basics of engines and maintenance but I’ve never tore into an engine to far besides most basic maintenance. My guess is there’s zero compression with the way it spins freely when I try to start it. I ordered a compression gauge to be sure but any help from y’all would sure be appreciated!

[squonk 41,378]

Sounds like a rod broke. The clue is "it took longer to shut off" 

[wallfish 17,083]

You can easily check for compression by removing the spark plug completely. Use you finger or thumb to block the hole and have someone hit the key to start. it should blow your finger out of the hole pretty quickly. A gauge is import for further diagnosis. Just keep the plug wire away so you don't get a jolt. If your finger stays in the hole while the engine is turning then something big, like a broken rod happened. With low oil like that it probably seized to the crank and snapped it.

[Ed Kennell 38,687]

No question, the crank bone is no longer connected to the piston bone.     I wouldn't crank it with pieces of the rod bone flopping around.

14 hours ago, ChickenPoop said:

. It turned and kept spinning freely.

 

[Pullstart 63,100]

Is it the black hood in this thread?  Unfortunately you may be best off looking for another “shaker plate” engine or plan to visit some small engine shops or automotive machine shops for rebuild quotes.  I am not sure if @richmondred01 can help?  He at one point had a high enough inventory of high quality rebuilds to be able to ship.

[WHX?? 49,177]

Where's that video of @Rp.wh  throwing a rod on the plow field when you need it. 

[richmondred01 2,239]

Sounds like a rod. I don’t have any 16 hp in stock. I can rebuild yours. The rod may have chipped the apron skirt when it broke. If that’s the case I sleeve the cylinder. Not a problem, unless the block is cracked, I can rebuild it. 
PM me for details. 

[Jon Paulsen 290]

4 hours ago, WHX?? said:

Where's that video of @Rp.wh  throwing a rod on the plow field when you need it. 

 

Will this 8 HP video work until you can locate @Rp.wh s proper rod tossin' vidjo?

 

 
Everyone loves to watch someone els's enjin toss parts out the case. 

[ChickenPoop 15]

Fun little update. Tore the motor apart. The cylinder wall and valves made out good. The rod is no longer with us. Looks like two of the gears had some chunks break off though. 

[richmondred01 2,239]

Most likely the bearings will also need to be replaced. When the rod breaks small pieces of aluminum get into the bearings. 
The crack can be brought back and ground. Not a problem. 
check the bottom of the apron skirt and see if it’s chipped.

Removed those balance gears. Also simply saying the walls look good doesn’t cut it. You need to get a cylinder bore gauge and measure it. 

 

[ChickenPoop 15]

8 hours ago, Pullstart said:

Is it the black hood in this thread?  Unfortunately you may be best off looking for another “shaker plate” engine or plan to visit some small engine shops or automotive machine shops for rebuild quotes.  I am not sure if @richmondred01 can help?  He at one point had a high enough inventory of high quality rebuilds to be able to ship.

Yes, it’s the black hood from that thread. 

[ChickenPoop 15]

1 hour ago, richmondred01 said:

Most likely the bearings will also need to be replaced. When the rod breaks small pieces of aluminum get into the bearings. 
The crack can be brought back and ground. Not a problem. 
check the bottom of the apron skirt and see if it’s chipped.

Removed those balance gears. Also simply saying the walls look good doesn’t cut it. You need to get a cylinder bore gauge and measure it. 

 

I’m wondering where y’all stand on the balancing gears. I’ve read up on it a little. Seems like I can leave ‘em or get rid of them. From what I’ve read, sounds like the risk of them failing and causing more damage isn’t worth what little vibrations they reduce?

[richmondred01 2,239]

Take them out. 

[WHX?? 49,177]

Only the most hardcore purist would leave them in. not one of Kohler's better mouse traps. 

[squonk 41,378]

2 hours ago, ChickenPoop said:

I’m wondering where y’all stand on the balancing gears. I’ve read up on it a little. Seems like I can leave ‘em or get rid of them. From what I’ve read, sounds like the risk of them failing and causing more damage isn’t worth what little vibrations they reduce?

You have a broken gear. It isn't balanced anymore.

[Tuneup 1,433]

I can't tell. Are those balance gears really broken? If not, send them to me. I'm becoming a purist.

[pfrederi 17,890]

I will take a contrarian view here.  Based on all the recommendations here I left the balance gears out of a K341 that I overhauled.  The engine has a very pronounced buzzy vibration now that gets to be uncomfortable after a couple hours of mowing...  Next big block overhaul will keep balance gears and get new bearings for them.

[Wild Bill 633 851]

I would think re-balancing the crank would allow the balance gears to be removed.

Edited June 21, 2023 by Wild Bill 633

[squonk 41,378]

6 hours ago, Wild Bill 633 said:

I would think re-balancing the crank allow the balance gears to be removed.

The crank, rod and piston are  balanced at the factory. Once you change a part the balance off to some degree. Balancing the crank would probably help but it won't be like brand new.

[RED-Z06 2,248]

I left my gears in on a 197hr old engine that broke a governor gear...i wish id left them out

[ChickenPoop 15]

We’ll I got a new piston, rings, and rod installed. Put new oil in. She started right up but started throwing white smoke pretty bad. Turns out I over filled the oil a tad. Drained some and got it just below full on the dipstick. Still throwing a lot of smoke. Can anyone point me in the right direction?

[squonk 41,378]

Did you hone the cylinder before installing the piston and rings?

[rmaynard 15,610]

Hope you put the rod cap on correctly with the oil hole toward the cam, or you will be doing this all over again.

[ChickenPoop 15]

What a way to learn! I’m going to know this engine inside out by the end of this! 

[ChickenPoop 15]

44 minutes ago, squonk said:

Did you hone the cylinder before installing the piston and rings?

No. Suppose I’ll be ordering a honing brush.