partsman 3 #1 Posted March 23, 2012 i have 1978 c141 auto 14hp kohler. it starts and runs fine cold you can mow for a 1/2 hr and then it just quits. it wont restart unless you use starting fluid. after starting fluid it will run another 1/2 hr and then the same thing. Share this post Link to post Share on other sites
Sparky-(Admin) 21,300 #2 Posted March 23, 2012 Check to see that the gas cap is vented. Mike........... Share this post Link to post Share on other sites
gregg'shorses 77 #3 Posted March 23, 2012 When it stalls immediatly check for spark. and report back. Share this post Link to post Share on other sites
Kelly 1,029 #4 Posted March 23, 2012 I'd start by opening the gas cap a few turns before you start mowing and see what happens, kinda sounds like a fuel issue. Share this post Link to post Share on other sites
WH854 44 #5 Posted March 23, 2012 I'd start by opening the gas cap a few turns before you start mowing and see what happens, kinda sounds like a fuel issue. DITTO Chas Share this post Link to post Share on other sites
rmaynard 15,417 #6 Posted March 23, 2012 What they said. I'll bet a nickle it's the cap vent. Share this post Link to post Share on other sites
partsman 3 #7 Posted March 23, 2012 yes guys plenty of spark. also loosned gas cap stil no help. fuel pump??? Share this post Link to post Share on other sites
bowtiebutler956 650 #8 Posted March 23, 2012 Take the fuel line off the carburetor, and crank the engine over to see if it is pumping fuel, but don't do it until it is acting up. MATT :flags-texas: Share this post Link to post Share on other sites
Wyattrrp 59 #9 Posted March 23, 2012 My '81 C-125 12 HP Kohler did that a few years ago. It didn't sputter or cough like starved for fuel, it just shut off after running for 1/2 hour. When cooled down it started and ran until hot again then same instant shut down. It was a bad condenser. But that would stop your spark so not much help I am afraid, but this may help someone else with similar problem. Now with the Kirk Pointsaver a condenser is not needed and it starts better all the time. Wyatt Share this post Link to post Share on other sites
gwgdog66 23 #10 Posted March 24, 2012 My brother's C-145 Auto was doing this when he first got it. We found a fuel can nozzle cap had fell into the gas tank at some point in the past. It would sink down over the strainer fuel valve and cut off the fuel flow, then float away after it killed the engine. We wound up having to remove the gas tank to get it out. Of course it was black and we couldn't see it in the black plastic tank. 1 Share this post Link to post Share on other sites
partsman 3 #11 Posted March 29, 2012 :) thanks for all the help guys!! it appears that the condenser was the culprit. i have my fingers crossed! Share this post Link to post Share on other sites
rmaynard 15,417 #12 Posted March 29, 2012 Guess I owe you a nickle. :hide: 1 Share this post Link to post Share on other sites
Wyattrrp 59 #13 Posted March 30, 2012 Partsman When this happened to me my local WH/Toro guy suggested a tune up with points, plug and condenser and if not solved look for a fuel problem. I mean it just shut off like turning the key. Cruising mowing full throttle 3rd gear and it stopped within 10 feet as the 12HP instantly shut down. No sputtering or coughing like being starved for fuel, which many times takes a few seconds if the fuel supply is not fully blocked instantly. To help trouble shoot the issue he suggested I replace all pts, plug, condenser eventually, but only do one at a time and see if the issue is solved. I replaced the plug and it still shut down after 1/2 hr runtime. So next I replaced the condenser and it never stopped again. Points followed a few weeks later as a followup to a full tuneup. Knowing the condenser was the problem I picked up another and had it on-hand just in case. Another post on here under engines I think asked how to test condenser and coils. As others said why test a condenser? It is too inexpensive to test, just replace it. To properly test my bad condenser i would recommend heating in the oven at 350 deg for 30 minutes then stick a fork in to see if it is tender, baste in 90-140W, rotate 90 deg then heat 10 min on 450, THEN run the test using oven mitts to avoid burned thumbs. Otherwise when cooled it would test fine, but running 1/2 hr it would heat up and fail. So just replace it. OR get a Kirk point saver and eliminate the condenser entirely and get a faster collapse of the coil field and bettter spark to start better. That is my story and I'm sticking to it !! Wyatt Share this post Link to post Share on other sites
gwgdog66 23 #14 Posted March 30, 2012 Glad you got it fixed! Share this post Link to post Share on other sites
tgranthamfd 29 #15 Posted March 30, 2012 My brother's C-145 Auto was doing this when he first got it. We found a fuel can nozzle cap had fell into the gas tank at some point in the past. It would sink down over the strainer fuel valve and cut off the fuel flow, then float away after it killed the engine. We wound up having to remove the gas tank to get it out. Of course it was black and we couldn't see it in the black plastic tank. It, also had the aftermarket fuel pump on it with the thin little gasket on it. we changed the plastic one out for the orginal metal fuel pump, which used the thin gasket, the plastic pumps have a thick one, something to do with the heat @ the pump and metal vs. plastic evaporating the fuel out of the pump because of being to hot. Both issues affected it but I don't remember which one actually fixed it. It's late and I am babeling now, sorry. Share this post Link to post Share on other sites