Engine quit today, now no compression
 

After a lot of work this past spring (http://www.onlycubcadets.net/forum/s...ad.php?t=37565), my 1200 Kohler k301 has run great all summer. Mowing and leaf sweeping today, and after about an hour it started to sound funny, like it was revving fast. I shut it off and when I tried to start again it would turn over but not start. After I turn the key off it keeps spinning much longer than normal.

Did some googling to figure out what it might be. I took out the sparkplug, turned the key with my finger over the hole, no air pressure. I can turn the engine by hand more easily than usual.

Based on the symptoms it seems like a broken connecting rod. I'm hoping one of you will tell me it's something simpler :Help:. Thoughts? What are my options and what should I do next?

Pull the tin ( sheetmetal ) and the head to see if the piston moves.

Sorry but from what you described, it may be a broken connecting rod. If not, it'll be a good excuse to decarbon the head and piston.

It may be a stuck exhaust or intake valve.

thats what i was thinking.

I can see the exhaust valve moving through the sparkplug hole. I just decarboned the head this spring as show in the linked thread. I'll have to pull the head again to see more.

You could also take the valve cower off and see what the valves are doing.

Is the piston moving?

I don't think so. How would I tell for sure?

Put a pencil or dowel rod down into the spark plug hole and rotate the engine, if it doesn't move, piston's not moving.

Is the spark plug hole in an AQS head over the piston?

I had a 12 hp engine once with a broken rod. It was easy to tell what was wrong. As the engine spun over on the starter, the front of the tractor kinda' bounced up/down in a rhythm with the engine. The bouncing was caused by the imbalance of the crankshaft with no rod/piston on it.

Another easy way is put air in the cylinder. You should be able to rotate the engine to a point that no air will come out either the carb or the muffler. If you can't, you have a stuck valve. If you can, you have a broken rod.

I just can't imagine an engine with a broken connecting rod continue to run until you decide to shut it off. I'm in with the "stuck valve" group.

Just pull the head and see if it's not then clean it up. I seriously doubt it broke a rod.

You should be able to see the piston move if you remove the valve cover breather and look at the small hole in the block that is next to the stud for the cover.

Rod or valve?:Huh: Enquiring minds want to know.:biggrin2: The suspense is killing meeee!:Explode: LOL!

I am betting on stuck exhaust valve based on the description. Yep pull the head again and see whats happening.
Regards,
Chris

Me too! Unfortunately other responsibilities beckon and it may be a few days before I can investigate further. I will update the thread with what I find.

When you crank it over do you hear any rattling, banging or unusual knocking nosises?

I removed the valve cover, they are moving fine. To the degree I could see through that small hole in the block, nothing moved when I rotated the engine by hand. I stuck a coat hanger in the hole and could not feel any movement.

There are some clunking noises when I rotate but nothing too loud, I'm not sure what would be normal.

Guess I'll pull the head off next.

Sounds like broken rod. Even if the lower skirt got damaged it still may be ok. Take some pics for us and good luck

Not what anyone likes to hear. I'd think if it broke a rod, you would known when she let go. Doesn't sound like good news though.

I've been following this thread and am reminded by my own experience, my K341 let go in 2001.:coffee: It threw a rod and broke the bottom cylinder skirt. All I had to do to repair the engine was to replace the piston and rod. I honed the cylinder, put it back together, and 14 years later it is hanging in my garage because I had to pull it out to repair the engine vibration dampeners. While it is out I pulled the oil pan and nothing in the pan. The only thing I'm going to check are the counter balancers and will check for a loose rod and so on.

Believe me, this engine had a rough life. My ex won the 1650 in our divorce.:bash2: Her husband used if for 12 years. He sold it back to me plus a parts 1650 for $250.:biggrin2: I'm currently adding dual hydraulics, front and rear, for driveway maintenance attachments.

These K series engines are tough.:Bowdown2: I'm rebuilding a 2nd K341 at this time. I'll be looking for a roller in the near future. Moral to the story, rebuild it, it'll be fine, and you won't regret it!:Salute:

I finally got back to this and took the head off. Bad news, as suspected the piston is not moving.

I was surprised to see the condition of the head - lots of carbon and crud, even though I had just decarbonized and replaced the head gasket in March. I only used it for mowing and light towing since then.

So now I'm wondering what could have caused the problem(s)? A few theories...

1. I got a new carburetor last winter, but the air filter didn't fit back on without interfering with the throttle linkage. I built a makeshift rubber gasket that I thought would provide some spacing and still keep it clean. When I took the filter housing off, it was really dirty and some of the dirt had gotten into the throat of the carb (sorry I forgot to take pictures before cleaning it).

2. I have a bunch of hills in the yard that used the cub to mow. I read somewhere this can cause lubrication problems. I had not been on any of the the hills the day the rod broke though.

3. Also with the new carb, the choke wouldn't fit on with the air filter. I ended up reversing the choke arm to get it to fit, maybe this screwed something up? I also had fiddled a good deal with the adjustment screws in the spring, I thought I had it sounding pretty good but don't have much experience so maybe it was too rich or lean.

4. The engine had been consuming some oil, I would have to add a couple oz. every 5-10 hours of use. The day it blew I had checked the oil it was about halfway between Full and Add. I didn't have anymore oil on hand and figured it was okay since it wasn't at Add.

5. I did something wrong when I cleaned the head in March

6. S**t happens.

So two questions:
- what do you think caused this?
- what to do now - what skills/tools/time are involved in a rebuild, should I try it myself and if so where to start, or anyone recommend a shop in Mass who would do it? If so how much should I be looking to pay?

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Aluminum rod just let go.

If this was my engine, this is what I would do.

These K series engines are awesome. They just keep running and running and running! I have rebuilt several of them the proper way by checking all the tolerances of the engine and so on. The use of oil is of some concern, but I have seen a K series that had over heated because of the cooling fins being clogged, the rings lost their temper and quit holding pressure against the cylinder wall, thus allowing oil past the rings and the burning of oil. In that case, the piston was still good and all that engine needed was a set of new rings.

If you know that the engine has never been apart, crank never turned and cylinder never bored. If the piston is not excessively sloppy (side movement in the cylinder), and the journal on the crank not grooved, I would just buy an engine rebuild kit like this one for $78 bucks. http://www.ebay.com/itm/Kohler-K301-...OE7GHmbYMBso1Q It comes with some instructions like the correct direction the rod and piston are to be installed. Yes they're after market China parts, but for $78 bucks, what do you expect.

Now I'm not here to start a debate on checking valves, valve seats, valve guides, crank tolerances, and so on. Yes there are a few specialized tools needed such as pullers, ring installation tool, ring compression tool for installing the piston into the cylinder, cylinder hone, and possible a ridge reamer, but I have been able to do all the work without these tools as well. I'm just suggesting a Saturday project that you could have done in a day. Heck, in this situation, I've even just bought a rod and put it in an engine and I can show you one that it is still in use a decade later.

You must be a do it yourself guy or you would not be a member of this group. If you have never taken apart an engine, why not try it yourself. Get a service manual. You can download a K series manual here http://www.kohlerengines.com/onlinec...df/tp_2379.pdf It will guide you on how to work on the engine. Also You Tube has a lot of how to videos if you run into a snag like removing the fly wheel or PTO. You also have a wealth of info right here within this Cub Cadet community.

Good luck!

I vote for #6

About 1988 I used to do yardwork for a neighbor that treated me like a son. I was on their 122 pulling a #2 trailer on the way back from my parent's house that wasn't far away. I went back to get some tools. Anyway, the engine quit all of a sudden. I tried to start it and the starter was spinning faster than normal. I knew it was bad.

I went back to their house and got the 1000 to tow it back. Upon inspection the connecting rod shattered in many pieces. The good thing is it didn't put a hole in the block. After 20 years it gave up the ghost.

The owners of the 122 considered not fixing it but I really wanted to give it a shot. I went over a few days later to do some yardwork and found a couple of Kohler boxes on the workbench. There was a new rod and piston waiting for me. I tore down the engine and replaced the parts. Looking back I should have bored the block but it was my first internal engine repair and I didn't know what I was doing 100%. When I turned the key it fired up.

I used the 122 on and off over breaks when I was in college. The last time I saw the tractor it was still running. Sadly they sold it sometime in the mid 1990's. I would love to have it today.

The 122 was used for sweeping the yard and plowing in the winter. They mowed with the 1000 that I own today. The 122 was bought new in 1968 with a deck that rusted out at some point. It hadn't been used for mowing in about 10 years when the rod broke.

If you are lucky, only the rod broke causing no other internal damage,as far as the block/cam etc.
but sometimes the rod breaks because of no oil, and it galls the crank. that is more work/expense.
looking @ the pix I'd say she was using oil and needed "freshing" long ago.
You will know soon enough when it is all apart.
Best of luck!

Have you pulled the pan yet? Are you sure it's the rod that let go?

The reason I asked is that, a number of years ago, the local fire station was using a "White" brand riding mower with a Kohler engine. Next to the building they had a fairly steep bank that they mowed along - steep enough that the fireman running the mower had to "hike out" and sit on the fender to keep the machine from overturning. One day it just stopped. The guy that did their mechanical work on the trucks said he'd pull the engine and overhaul it. What he found was that the top of the piston separated from the skirt!

He theorized that, at the extreme deck angle that they were using it, the splash lubrication wasn't getting enough oil up under the piston, and it just melted through right at the rings. Anyway he fixed it by just replacing the piston.

I have a 10hp Kohler in a 1000 that was running when I parked it. I had left it sit with no attention for probably a couple of years. One day I decided to start it, so I charged the battery and when I hit the starter it made a bad noise. Piston top isn't moving, but it turns over. I bet the same hing happened to it - I just haven't had the time to tear into it.

In my opinion if you going to buy new parts you should buy an oversized piston and have it bored, I don't think it's money well spent to buy a new piston and slap it in a worn out hole because it will just be a band aid repair.

Don't start buying parts until you get the thing completely stripped and have a machine shop MIC it. Most folks don't have the calibrated eyeballs to know when the cylinder has gone egg-shaped. They may advise anything from boring the cylinder to turning the crank down.

Get your facts gathered up front.

Well....if you had and one of the 1 thru 5 happen too you, number 6 is automatically included.

Number 4 is my bet.... had a smoker.... a bad smoker. Piston/rings sloppy loose. Worn. Look how much carbon/oil deposits on piston and heads already after a new head gasket in March.

Pull the bottom and have a look-see before doing anything. If things look good, the machine shop is your new friend!

I'm thinking the same thing. Either way, I am hoping to find time to tear into it this weekend and wil report on the status.

Bag your ur parts and Take pictures so you know what goes where on the Engine.

Funny how time changes a man----
50+ years ago I'd pull apart a small block chevy and throw the small parts in a 5 gal bucket of kero
some weeks later, maybe months, I'd wash parts and re assy knowing where each went just by the look of them or length/size.
Today, I can't remember what I had for B'fast or If I ate it!! Ha,LOL!:crap:
Enjoy youth guys, it is fleeting!:angry:

You say you are surprised to see the carbon in the chamber, but after reading this #1 and looking at the pics, this is most of the cause of your carbon. Carbon is simply what's left behind that won't burn. Yes, oil can cause it, but so will dirt. From the looks of the pics, I can say for sure your engine was ingesting dirt. Did it cause your rod to fail? Very possibly. Did it excessively wear your cylinder? For sure.


It doesn't cause lubrication problems..... it is a lubrication problem. The engine is splash lubed off the dipper on the rod. If it doesn't have oil to splash because it's all hanging out in the corner from being tipped.... it's can't lubricate. Did it cause your rod to break.... I'm sure it didn't help. But not likely the cause.


The choke has to open and close all the way to do it's job. Did you adjust it correctly..... no way to know. From the looks of it, it looks a little rich.


Not likely any effect on what happened. Not unless it suddenly burned it all.


Not likely at all the cause of rod breakage.


All the time.


Most likely cause: Age

Should you do it yourself.... all here will likely say "YES" except me. I say NO. One should know what they are good at and stick with it. Can we all learn new things? Sure. Do you want to learn? Do you have the $$ to tool up and are you willing to accept what happens if you do it wrong? That's up to you to decide. I say pay someone. When I rebuild them, they wind up in the $6-700 dollar range. Give or take what the customer wants. :beerchug:

(Not that you will ask me, but no, I will not do it. I would like to get back into offering that service, but I am simply too busy right now.)

Great post J!

This was my favorite! :beerchug:

Quote: ccollins0601
6. S**t happens.

All the time.

It does too! :biggrin2:

I just put a k321 on the floor from a 149 that's doing the same thing, I took another 321 from a 147 and put it in the 149 so I'll be able to use the snow blower this winter. Can't use the 147 for anything but towing as the electric lift is broken. Going to take the pan off and see what happened this week. I've had the 147 for about 20 years, and the 149 for about 5, and nothing has ever gone wrong, now they both break the same year. Oh well.

I finally got the engine out and apart. Here's what it looks like. Looks like a chunk came out of the bottom of the cylinder. Is this engine rebuildable, or no good?