1250 Stalls when hot. Cools down and then starts like a champ

[llapple]

My 1250, purchased new in 1980 runs like a champ. Over the last year It started stalling after about an hour of use. It would try to start if I gave it full choke, but just ran very roughly then stalled again. I have rebuilt the carburetor, and having read some comments on Kohler engines have adjusted it on the rich side. Once it cools down, it runs like a champ again. Anyone have a similar problem and have a solution? I still haven't figured it out. My friend calls it the two beer tractor. Cut for a while, stall, have a beer, cool down, finish the job.

 

[jstich]

Stens 455-147 Condenser, Replaces Kohler 230722-S
Amazon,com $7.35
Or go to your friendly local NAPA or Autozone and get an old 6 cylinder Chevy condensor for about $4.00
Worked for me, many times

 

[kmcconaughey]

Agree, replace the condenser.

 

[dfrisk]

I had that identical problem with ignition coils. If when the tractor dies, the coil is too hot to touch, replace it. Use the stock Kohler coil or the Bosch blue coil.

 

[stucker]

2nd the coil. Your description is exactly how a bad cool acts - windings heat up and open electrically. That’s been my experience.

 

[llapple]

I had that identical problem with ignition coils. If when the tractor dies, the coil is too hot to touch, replace it. Use the stock Kohler coil or the Bosch blue coil.

I had that identical problem with ignition coils. If when the tractor dies, the coil is too hot to touch, replace it. Use the stock Kohler coil or the Bosch blue coil.

 

[llapple]

Thanks so much...I will check it out and give it a try!

 

[dkirk]

Next time it stalls, check for spark. This will confirm if the problem is ignition related. Use a known-good spark plug, swap ignition wire to the good plug, rest plug on engine and crank it...an easy test.

Problem could also be related to a sticking exhaust valve. When engine stalls and your cranking it via the starter, does it sound like there is compression? You might want to try turning the engine through by hand to feel for compression. If engine spins freely, then exhaust valve could be partially stuck - a somewhat common problem on high-time engines. You might try the "chemical overhaul" by using Marvel Mystery Oil or Sea-Foam in the gasoline. May take a few tank-fulls to remove the carbon build-up between valve stem and guide, but this stuff is amazingly effective.

 

[btaner]

If none of the above doesn't solve your problem, check under the tins for a mouse nest. I had the same problem, i pulled a whole coffee can full of debris from the shroud. Brad

 

[dschwandt]

Use a test light and check the wire to the points while cranking.
Easy 1st test as you do not need to take anything apart.
Check the wire TO the condenser. may be loose in it, then when it feels hot, the insulation swells and breaks contact.

 

[rchristensen]

If the condenser, or coil suggestions don’t fix it I would suggest looking at the head gasket. I have seen those symptoms with a bad head gasket. The tractor would run fine until it got hot and the gasket would open up, tractor would stumble, choking would seem to help but then it would quit. Let it cool down for 15 minutes and the gasket would seal and compression return and tractor run fine again till it got hot. If the gasket is bad you usually see what looks like burned oil down the side of the cylinder below the head.

 

[abthomas]

I'm having the same issue with a 1450 ! my thoughts are the same ,I'm going to pull the head and have a look, done everything else,points,plug,plug wire,carb,condenser,coil,timing,and valve adjustment runs fine 8-10 minutes then loses power and will only run at a fast idle,let it cool down and it runs fine for another 5 minutes !

 

[sblunier]

Dont over look a plugged fuel cap vent......can pull a vacuum and starve the carb.

When it happens, open cap, listen for air rushing in, try to restart

Probably ignition, but can be fuel.

 

[abthomas]

Here's what I found ! Pulled the head,several bolts were fairly loose one corner of the gasket showed evidence of some leakage,likely when it warmed up and bolts grew a little, no evidence of carbon build up,valves looked good-cleaned and relapped them for good measure ! Reassembled,warmed up and retorqued the head,ran good for the same 8-10 minutes ??? The one thing that tested good when I static timed it several weeks ago were the points so I didn't look at them again until today when it still wouldn't run at more than half throttle, found screw that holds wire on points stripped and backed out with wire out from behind screw altogether,don't know how it ran at all yet alone good for 8-10 minutes ! The only thing I can figure is the motor got warm and the wire became soft and lost good contact at higher rpm! Not regretting pulling head with loose bolts though needed done but lots of searching for this problem though, as I initially looked at the points and adjusted weeks ago without seeing any issues ! Hope my info helps others !!

 

[CaptainShwammy]

The world is a better place now. Lo and behold, someone came back and told what the problem ended up being. Excellent!

 

[wh cc guy]

You are right. That doesn't happen very often.

 

[dsarow]

Thats part of why I read a question that might pertain to my situation. I'm hoping for a lot of input from other members.Experience comes forward,thinking caps put on.The suspense is building,and the owner solves the problem,after all the members help him.He puts the frosting on the cake,and we all benefit.Thats why I read and enjoy this site,and happy the member fixed and communicated the issue.

 

[bwilkinson]

A lot of good information on this site. I have been going back and reading old post that help me while starting to work on my 126. Maybe some day I will be able to post something I was able to solve with my CC.