1250 Engine Trouble

[dwhipple]

Ok guys, I'm having trouble with my 1250 K301AQS engine. I have replaced the coil, points and condenser. I have also removed the fuel filter and ran a fuel line from the tank directly to the carburetor, warmed the engine and readjusted the carburetor. I then started mowing my grass, mowed for about 70 feet and the engine shuts down. It didn't sputter or backfire. Cranked the engine and it started right back up at idle but for some reason, even with the engine warmed up, it will not start up with the throttle opened without choking the engine. After restarting the engine, I managed to mow some more and this time before it shut down the engine was hesitating (like a miss fire) this time. I don't have the money to take it to a repair shop for a major overhaul right now so I'm trying to fix it myself. Any help would be appreciated to get it properly running.

Thank You

 

[kashaver]

Well, it sounds like you are not getting enough gas flow to keep going.

Have you looked inside the tank for trash?

Have you removed the fuel hose and just let it run to verify that there is no restriction? I mean a good stream for a minute or more. Let it run into something clear so you can check for trash. Also, sometimes the inside of the hose itself deteriorates and chunks break off and cause problems.

Have you removed the bowl from the carburetor and checked for trash? Sometimes trash in the bowl will fall away from the jet and you can re-start the engine, then it plugs the jet again.

If you have a good flow from the hose, re-connect it and check for flow through the needle valve. Trash sometimes gets stopped by the needle.

I know you were just trying to test it, but its not a good idea to run with the fuel filter removed. Any trash coming down the line can go right to the carburetor.

There is also the possiblity you are losing spark. Without putting an in-line spark tester in the line, I don't know how you could tell.

 

[dwhipple]

I did clean the carburetor and the fuel bowl and checked the fuel flow from the tank into another container and it was fine. Spark seems to be good also.

 

[dschwandt]

Pull the shutoff valve from the tank to flush the tank and check for a damaged and/or plugged screen on the valve. It sticks up inside the tank.
Also make sure the float is properly adjusted.

 

[dgunn]

Sounds like you might have a sticky valve. It happened to me once with a K301. Running just fine blowing snow and then just like someone turned off the ignition. Would start back up and run just fine.

 

[mstone]

Same issue here, check main fuse for corrosion, It happens here.

 

[dschwandt]

Main fuse??
There is no main fuse on a 1250 unless of course someone has cobbled on in somewhere somehow.
Only fuses are for lights (if equipped) and PTO.

 

[mfrade]

I think David S. is right. I'd say check the small screen in the tank also.

 

[dray]

Compression test will tell if you have internal problems

 

[dray]

Also have you checked fuel cap for tank ventilation. Start with the basics and verify the simple things. You might want to put a fuel filter that allows you to see the fuel.

 

[dschwandt]

I'd try an oil change w/MMO and a double dose of the same in the fuel.
Then get it running and idle it up in RPM's and let it run for 1/2 hour or so.
I use it in all my unleaded non-ethanal fuel 1/oz per gallon\
A compression test and ACR don't play well together.

 

[dclinansmith]

I have had problems with two 1650's that were very similar to the symptoms you describe. I focused on fuel problems both times. One problem was resolved by replacing the coil which probably didn't have a whole hour of run time on it, the other was a bad condenser. Both times the guilty party was a new part.

 

[scfenn]

Compression test will tell if you have internal problems

How do you do a compression test with ACR?

 

[kmcconaughey]

How do you do a compression test with ACR?

From an IH-Kohler Service Manual:

 

[dray]

Great information on compression test. Also check valve clearance to help with accurately of the test. Your in a good place for information, these guys have a vast knowledge and are here to help. Just like Allstate your in good hands !

 

[kaweimann]

Bad condenser had me going nuts. I bought a new one that was bad out of the box, even bought a cheap Chinese Cap tester to confirm. Once a "good old one" was installed, she started with no choke and revved up just fine.

 

[dray]

Good deal. Glad to hear

 

[llapple]

Had a similar issue that my 1250 would stall when hot and would only restart with the choke on. As soon as it cooled down, started like a champ. Read an article that the K engines like to "run rich". I adjusted the carb to a bit richer mix and had not had a repeat issue.