Cub Cadet LTX 1142 with Kohler Courage 19 HP SV470-620 engine. Two years old with 87 hours on it. Problem started about a year ago. Lawn tractor cold-starts and runs without a miss. If I stop it and re-start within a few minutes, it works. If I leave it off for more than, say, 15 minutes it will not start....not a hint of firing. Not until the next day, when it will start and run normally. After a couple of times when I had a load of firewood or branches and leaves in the dump cart away from the storage shed and having it not start, I have since just left it idling while I raked, bucked or shovelled. Idles and runs faultlessly for hours.
I checked and fiddled with the brake, seat and PTO interlocks. The spark plug is cleaned and wire-gapped to 30 thou. I put a momentary push to open switch in the oil pressure sensor to monitor circuit (no effect). Another "Ask" website expert gave up.
I think something gets overheated from stored engine heat when the rotation of the coooling fan stops. But what? Is there a condensor somewhere in the magneto circuit that is heat sensitive?
We have to find out if it is a fuel or spark related problem. I am leaning toward spark. Next time it happens check to see if you have spark. If you have spark I am wrong (the first time ever) and we will address the fuel problem. First thing on a fuel problem is the check to see if the pump is working under hot conditions by removing the fuel line going to the carb and turning the engine over. Hopefully you will see fuel and we will go to the next step.
I forgot to add: Occasionally (like today, two times) on a hot start after longer than 15 minutes, the engine fires-up immediately and dies within a second or two. If I am lucky, after a few seconds cranking, it will run. Most times, no amount of cranking, 8 to 10 seconds at a time, will get it to start again, until the next day.
This engine, otherwise, when it starts, it runs as soon as it starts with no misses or hesitations.
I guess checking for spark is a two person job? First the plug is buried deep in the cooling shroud. Second, someone has to sit in the seat and also depress the left (brake) pedal and turn the key to get the starter to connect. I'll have to get my wife involved!
#4
SONOFADOCKER
Are your fuel lines dry or brittle ( sucking air ) is the carb bolts tight and manifold boats tight ?
Pull the plug out and look at the cylinder top with a light - look for carbon build up .
If the cylinder is dirty the carbon is hotter than the spark plug spark . As soon as the fuel is going into the cylinder it is burning before compressing stroke reaches top dead center .
It will not start until its cool .
That's why you have spark and a wet plug ...
Many machines come into the shop with the head loaded with carbon .
I removed the spark plug this morning. It had a very low coating of carbon. I ran fine emery through the gap and checked the gap with a wire gauge; confirmed to be 0.030".
I'll look at fuel lines, carb. bolts, etc tomorrow. The unit is only 2 years old and has been stored in a well ventilated shed.
Thanks so far, but no Eurekas!
Checked carb bolts...tight. Fuel line in good shape, as expected for a relativel;y new unit.
What about that "anti-afterfire" solenoid on the bottom of the float bowl? I see some posts say I should here a click when I turn the ignition key to the run position. I hear nothing.
Held the solenoid body and turned key on-of several times, just to "run" position.......nothing!
Any recommendations for next step?
I presume I should disconnect and remove it from the float bowl. There is no fuel shut-off valve, and the tank is full. I guess I have to remove the connected tube and lift it high enough not to siphon out? Minimize gas all over!
Instructions say replace fuel filter every 100 hours (not there yet) but they don't say how. Maybe there is enough loose line to raise it up above tank level, and that will allow removal of anti-afterfire solenoid
P.S. - Thanks to advice to "test & start in park". I feel dumb....I use park all the time, but store the tractor without setting park. I just never tried starting ir unless I was in the seat!!!!
Ok, we have a place to start. First, how to stop the fuel flow. Take a vicegrip pliers and set it so when clamped over the fuel line no flow. Now you can remove the solenoid. You fill need a thin 1/2" or 9/16" tappet wrench. You may be able to borrow one from your auto mechanic. Unplug and remove the solenoid. Let's do one more test at this time. Hold the case on the neg. terminal of a battery and attach a wire to the solenoid wire and jump it to the pos. terminal. Does the plunger move. If no replace. Let me know what happens.
I disconnected the feed wire to the solenoid. I ran a jumper from the battery positive to the solenoid feed....no feel or sound of action.
I connected a DC voltmeter from the solenoid power source wire, and turned the ignition to start, getting the expected controlled voltage of 9-10 volts. So the system tries to power the solenoid allright, but I guess nothing is happening.
Before I remove the solenoid, I'll check tomorrow with one of the local service stores....I think some Sears lawn tractors have Kohler Courage engines, and maybe have parts. Otherwise, the nearest Cub Cadet dealer is over 100 km away, and I want to know I can get a replacement before I remove the old one.
Thanks again!!!
They make a testing bypass plug just for this. If you have a hardware store take the sol. with you and match the threads up might be 1/8th inch pipe. I put one on mine 6 years ago and it is still there. This was on a JD LT180 so the way the fuel line and pump is laid out allows this to work. I have never had it backfire wont hurt to try it. The John Deere dealer told me to take side cutters and snip the end of the plunger off:laughing: It is NC so without power the plunger is spring loaded closed and pulls open with 12v.Mowers worked for many years without these things. Then the EPA came along.
Ken
#14
SONOFADOCKER
Tree huggers should chew our lawns like grazing cows
