1250 STILL won't run. I give up! HELP!

[Matt Kirsch]

I've tried ALL the conventional remedies, multiple times. This engine WILL NOT RUN!

I'm ready to admit defeat and push it to the road.

I disconnected the engine from the hydro pump.

It will run for about 2 minutes at full throttle, then it slowly idles down, and stops.

Crank it, and it starts right back up and runs for another two minutes, slowly idles down, and stops.

I can't count how many times I've had the carburetor apart, cleaned out every hole and orifice, set it to factory spec, and put it back together.

[Jeff in Pa]

Have you tried a different coil?

[Froghunter]

Look at all the fuel system! Not sure if it has fuel filter or screen, but check it. On my CC104 if the sediment bolt was to tight it would starve the engine and it would die, but I kept trouble shooting it until I got it right. Keep at it and you would get-it!

Froghunter

[SundaySailor]

Ok Matt. Time for some unconventional wisdom here. You've rebuilt the carb, right? Do you have fire at the plug when it shuts down? Do you still have fire? If so, here's where I'm going to direct you.

I've just finished going down the road you are at right now with a 1200 Cub Cadet. We have pretty much the same machine. Mine is a straight drive, your's has the hydro. Ok?

Something I found out: This line of Cub Cadets has that dang heavy muffler hanging off the front of the engine. It has a tendency to break at the mounting points. One of those is in the air duct to the right of the tractor. The other? It attaches to the exhaust pipe on the left side of the tractor.

I cannot tell you how many used mufflers I looked at on ebay that were cracked right around the mounting for the input exhaust port. I finally ended up buying a brand new muffler from C&G. Best money I spent on this tractor besides getting the engine rebuilt.

Now then, with the exhaust flange being broken so easily, this has a tendency to BURN the exhaust valves on these engines.

The exact same things you are speaking of with running for a short bit then shutting down were happening to me. I rebuilt the carb, flushed the tank, had great spark, the whole nine yards. It ran fine cold, but when it just started to heat up, you couldn't get it to run worth a flip.

I yanked the engine and sent it to a machine shop for a rebuild. The machinist called me back and had me drop by the shop.

The exhaust valve had a burned flat spot that faced the exhaust pipe! As it heated up, the valve would expand and stop sealing properly. No seal, little to no compression, no pulling fuel properly, and it acted like it ran out of fuel.

Pull your hood, your front grill, your cooling tins and then the muffler. Check the input on the muffler that the exhaust pipe goes into. Bet you a RC cola and a moon pie it is cracked just like all the rest I've seen. On top of that, I bet you have a burned exhaust valve.

Remember, these tractors have been driven into the ground with little to no proper maintenance. They also are prone to excessive vibration and this lends to sagging ISO engine mounts, bad drive trains (yes I dealt with that too), cracked mufflers, and who knows what else.

On a positive note, I drove mine around the first time yesterday with the aerator as a test drive after my restoration. My 18 HP Simplicity doesn't have the power my 12 HP Cub Cadet has and the Simplicity is about 20 years newer!

Don't pull your hair out. My head is bald enough for both of us. It'll take you all of about 30 minutes to pull it down as far as I've suggested if your bolts come out as easy as mine did. I'm glad I went into it as far as I did. Now, I'm into the testing and re-tightening phase.




Oh! Don't run your Cub Cadet without a muffler. You are only asking for trouble - as in burned exhaust valve.
I love my Cub Cadet!

Let us know what you find out. When I get time, I plan on doing a write up with photos of what I ran into in the rebuild of my Cub Cadet. It's the least I can do after the good folks here helped me out like they did.

[Matt Kirsch]

Ugh, that's got to be it. Acts like a sticking float, right?

When I got it, the muffler was just rattling around inside the compartment. It had been broken off at the inlet before.

[bandit86]

just because the carb is set to factory specs dowsnt mean it's right. run it till it's warm a,d do the setup running. mine needed to be set up with the mower going to get it to stop acting up, but mine is an all original 1971 kohler. ran good cold but quit under load after 2 minuts. needed to set the carb with mower engaged

[wdeturck]

You rebuilt the carb but did you fix the slop that develops in the carb shaft? When they get real bad it's hard to get the hi jet set and they get to much air to set the low at idle. If you can find a Hillman 5807-A bronze thrust bushing(1/4" x 7/16" OD) sold by Ace hardware they are a lot cheaper than the Kohler repair kit.

[Matt Kirsch]

Adjusting the needles on the carb doesn't help the problem. All it does is make the engine run rough and blow black smoke if I get too rich, and die immediately if I get too lean.

It will run a while and quit even when it's blowing black smoke.

Carb shaft is nice and tight, amazingly enough. Despite how it looks, I think it's a fairly low-hour tractor.

At this point, I'm done messing with it. Out the door it goes. It's taking up too much space and I don't really have any interest in fixing it.

[SundaySailor]

Ugh, that's got to be it. Acts like a sticking float, right?

When I got it, the muffler was just rattling around inside the compartment. It had been broken off at the inlet before.

Matt,

Sorry to be late in responding. I set my float level with a digital caliper so I could see the numbers lining up. No matter what I did for adjustments on the carb, it would run when cold, but as soon as it warmed up some, it would not run at idle.

I'm sure at this point the PO had jacked up the governor so it would maintain rpms at high speed and run long enough for a dummy like myself to buy it. After rebuilding the carb like I did in relation to my Farmall Cub, I knew it was more than just the carb.

At that point, I acted like the Queen of Hearts in Alice in Wonderland, and it was "Off with its Head!" so to speak.

The machinist's tear down found the burned valve as I wrote about before. Fortunately, the total number of hours on the engine were apparently low as the bore on the block was only .010. So, I have effectively a new engine in my tractor now.

BTW, she runs on the high end, middle end, and purrs like a kitten at idle. Amazing what a burned valve can do. Oh, I didn't do a thing with the carb after the engine rebuild except follow the book on setting the high speed idle screw and the low speed idle screw. In other words, my carb rebuild was on the mark to start with.

This is one pulling tractor! I can't wait to get it broke in and do some field plowing with it, not to mention snow plowing with that out front snow blade.

Good Luck with the progress. I wouldn't throw out the baby with the bath water if I were you. You have a fine machine there if you work with it. Too bad I live a tad too far from you. I'd be happy to help you out.

SS

[Matt Kirsch]

Hmm, this one would quit at wide open. It would slowly start losing RPMs over about 30 seconds until it finally died.

Anyway, it's a headache I don't have anymore. I put it on Craigslist, and it went out of the yard on a trailer yesterday afternoon. I've got space in my shed, and money in my pocket for my time and parts.

The only reason I ended up with it was because it literally followed me home. My next door neighbor's Lexus had an unintended acceleration event, and sent him plowing into the garage where the tractor was sitting. The car hit the Cub Cadet. Did more damage to the car, but pushed the tractor up against the wall so tight he couldn't move it.

He came over and asked if I could use one of my tractors to pull it out. I'd like to say I used the Cub, but I actually used the Super A with the 1000 loader, so I could lift up on the front while I pulled it free. While it was chained to the tractor he asked if I wanted it, as he was just going to have me drag it to the road otherwise. He couldn't get it to run right either, and had bought a new mower.

So, it literally followed me home... on the end of a chain.

I really had no interest in it, other than to get it running and use it for a yard tug. Burned valve, though... Too much work, too much $$$, not enough time, and no real reason to do it... So it's gone to a good home.

[Matt Kirsch]

Oh yeah, and wouldn't you know it, but the %$#@ed thing ran PERFECTLY when the guy came to pick it up. He drove it all the way to the front yard and up on to his trailer. It never missed a beat.

I could never get more than halfway from the shed to the house before it quit.

I think he was grinning like the Cheshire cat as he drove out of the yard...

[SundaySailor]

Well Matt, under the circumstances, I have to understand you getting rid of it. The person who sold me the 1200 Cub Cadet told me all kinds of outright lies about the tractor,and I was stupid enough to buy it anyway.

Cub Cadets in my area come far and few between. I waited around 5 years to find this one. Now that it is almost finished, it will stay with me for quite some time.

As far as your former Cub Cadet running like a top when it left, I couldn't help but chuckle about that. Years ago I had a 1995 Chevy S-10 that was getting some high mileage on it. It was running fine when I just happened to pull up to a auto dealership to look around. When I got back into the truck to leave, not only did it start to snow, but the battery was completely drained!

Apparently one of the cells in the battery decided to short out right after I stopped the truck. I swore up and down the truck did it to me on purpose just for stopping at the car dealership. Fortunately, I was able to get someone to help jump me and I made it to the Autozone where they replaced the battery under pro-rated warranty.

It just goes to show some of these things might actually be alive after all.

[Matt Kirsch]

Cub Cadets in my area come far and few between.

While we were loading the 1250 up, some shirtless dude in a beat-up Oldsmobile pulls in the driveway, gets out, and says, "Hey I see you're into old Internationals. I've got a 1250 that's in cherry condition but it's started to pop out the exhaust. You interested?"

Suffice it to say, I declined his offer. Didn't want to hear a price. I want money coming IN, not going out...

[mikethefixitman1]

Matt
I have not the time to read every reply to your problem. Check several things.You say it runs at full throttle for several minutes and then slows down and DIES. FUEL TANK VENT. Then next thing check that air-filter. I have a 17 hp Kaw(brand tractor un-named) that I just cleaned the fuel tank and screens,replaced the fuel-lines and filter,cleaned the carb., reassembled the air box dropped in the filter (with it running) and after all that work it DIED. I started it up and did the same over again IT DIED. I pride myself on keeping filters changed but this one was for some reason clogged( it didn't appear clogged) and was chocking the air off to this engine.
I will return later and read this thread again to see if ya found the problem. Even at this late date people are keeping my little shop FULL ,by breakin stuff.
GOOD HUNTING
Roger