Engine Engine Sputters and Dies

[Dave123]

Mower starts right up, give it full throttle and engage blades mows less than a minute then starts to sputter and dies. It will start right back up and do the same thing again. Changed fuel filter, checked gas cap vent, spark plug cleaned and gaped. Fuel tank still 1/2 full with the same gas the that I mowed with last week, what is next?

Engine is a Kohler Courage 19, SV590S.

 

[EngineMan]

Take out all of the old fuel, yes I know it may well be just a week old but...! look for water in it, then clean the carb.
look for a faulty or fouled spark plug.
spark plug lead boot loose on plug.
loose wires or connections that intermittently short the kill terminal of ignition module to ground.
engine overheated.
faulty ignition module or improperly gapped.
vent in the fuel cap restricted.
faulty cylinder head gasket.
Run with new fuel.

some of the above you may feel you have already done, but recheck them.
Come back if you feel you need more help.

 

[ranchhand]

I will tell my story as some of you have described similar troubles, I purchased this CC LT 1045 with 42" cut, used, last spring. A month of use and the Kohler courage 20 Hp started losing power and sputtering and then backfiring. It would always restart and run until put under load. I,read of several similar problems on here, talked with a small engine mechanic and started some actions. 1st, changed fuel filter, no help. checked vent on gas cap, changed gas, blew out fuel line, no help.
I noticed that oil filter was an inexpensive brand and assumed the oil was also(changed before I bought so it looked clean). I drained oil, installed Amsoil 4 stroke small engine oil, put on a new Napa oil filter. Added Amsoil "Quickshot" to gas. It took a month to get to running better. At first it would go a short time and die again. The time started getting longer each time. Now, after about 2 months it seems to run normal. I mow approx 2 to 3 acres and it will do 2 to 3 hours and not fail now. My thinking is that it had to do with hyd lifters being gummed up and not functioning, and the hi tbn oil and varnish cleansing product slowly cleaned the engine so it could work normal. It would have been very costly to have a mechanic tear down to repair or replace hydraulic lifters or what else he would find, so I am happy!.

 

[Dave123]

I will tell my story as some of you have described similar troubles, I purchased this CC LT 1045 with 42" cut, used, last spring. A month of use and the Kohler courage 20 Hp started losing power and sputtering and then backfiring. It would always restart and run until put under load. I,read of several similar problems on here, talked with a small engine mechanic and started some actions. 1st, changed fuel filter, no help. checked vent on gas cap, changed gas, blew out fuel line, no help.
I noticed that oil filter was an inexpensive brand and assumed the oil was also(changed before I bought so it looked clean). I drained oil, installed Amsoil 4 stroke small engine oil, put on a new Napa oil filter. Added Amsoil "Quickshot" to gas. It took a month to get to running better. At first it would go a short time and die again. The time started getting longer each time. Now, after about 2 months it seems to run normal. I mow approx 2 to 3 acres and it will do 2 to 3 hours and not fail now. My thinking is that it had to do with hyd lifters being gummed up and not functioning, and the hi tbn oil and varnish cleansing product slowly cleaned the engine so it could work normal. It would have been very costly to have a mechanic tear down to repair or replace hydraulic lifters or what else he would find, so I am happy!.

Pulled carb, it had sediment in it. cleaned it. Changed oil to Mobil 1, added fuel additive for ethanol gas, cranked right up and runs like a champ for now. Looks like I was pretty lucky. I was hoping I would not have to dig to deep as I bought the mower new and the hour meter only has 37 hours on it.

Thanks everyone for you ideas and help.

 

[lawn mower fanatic]

Pulled carb, it had sediment in it. cleaned it. Changed oil to Mobil 1, added fuel additive for ethanol gas, cranked right up and runs like a champ for now. Looks like I was pretty lucky. I was hoping I would not have to dig to deep as I bought the mower new and the hour meter only has 37 hours on it.

Thanks everyone for you ideas and help.

:thumbsup::thumbsup:

 

[banjopicker]

i have a 24 hp briggs in a 1024 cadet 2005 or 2006 model,,, it does the same thing but ONLY after it gets hot,,, it may take an hour before it starts it. it starts out surging rpms.. play with choke and it wil smooth out,, then it starts sputtering and will eventually cut off,, turn off the pto and it will restart,,, runs a few minutes then the same thing,,, changed fuel filter,, went to 93 gas,, other then that it mows and runs great,, it has 451 hours on it now,,
any ideas?


thanks
terry m

 

[Fish]

First, easiest, cheapest thing to do is check and adjust your valves.

 

[greynold99]

Hi Terry,
As you commented in your initial post, I'm one of the other posters reporting a very similar problem with a 1996 Cub 2135.
The only symptom I don't have is the 'surging'... other than that, your description is identical. I've arrived at some conclusion that the accumulated heat build-up after an hour or so operation time is related to the problem - though I don't know how exactly.
Now that our outside temp is 70 degrees or less, I've mowed a couple of times with absolutely no problem mowing, as recently as last night for over 2 hours. Typically on a warm or hot day, I'd mow an hour and then have to start playing with the choke to keep her running. Then once she recovered, I could mow a while longer, maybe 5-10-15 minutes before I'd have to repeat the process of disengaging the mower blades and playing with the choke - pulling it out about half-way to keep it running. Only 1 day in the Summer when the temp. was 90+ did it stall out and I couldn't get it started but after it cooled, it started right up.
The problem seemed to appear most often when mowing a slight uphill grade or when mower was under load cutting high grass; but the heat build-up seemed to be the common factor.
I also have already replaced: ignition coil, rebuilt carb, changed Fuel,Air filters, Oil & Tranny fluid/filter, spark plug. Also replaced the fuel line clamps with the small stainless screw-type clamps but have not yet replaced the flexible fuel line itself.
I've been advised to change the carb and just put a new one on; although the fact that it runs perfectly for at least an hour in warm weather or longer in cold weather doesn't seem to me to be something that matches a dirty carb problem. Although just to cover all my bases, I have been adding a little Techron fuel injector cleaner each time I fill up the fuel tank the last month or so.

I did finally contact Kohler Engine (the 2135 has a 12hp OHV Command) to see if they were getting any similar reports - and after 2 months, I got a call from my local Cub dealer serviceman. But he didn't offer anything new beyond suggesting I change out the carb for a new one.
One last thing, one forum reply indicated someone found a small piece of plastic in the fuel tank that was periodically covering up the outlet for the fuel line.
He couldn't see it by looking in the tank but drained the tank and found it that way.

If you find anything, I'd sure like to hear about it.
Thanks,
Greynold99

 

[EngineMan]

Fit a temp fuel tank with new fuel line to the carb and see if that make's any difference.

 

[packardv8]

My 2135 has exactly the same symptoms. I also have tried all the above remedies. If it were an older car, I'd now say we're seeing vapor lock.

Today's fuels are formulated for fuel injection and have lower vapor pressure than for carbs. Many old car guys report more problems with heat soak, vapor lock, carb boil-over, hot starting. Keeping the fuel tank full adds to the pressure head so the fuel pump doesn't have to work as hard. Set the float bowl level to max drop specification

Also, I'm putting more emphasis on keeping the engine cooler. Blowing out all the dirt and trash from the shroud, running the oil level slightly above full, using 15w-40 in the 90+degree mowing.

jack vines