[Miccol]

Asking for some knowledgeable assistance on my Kohler CH18 engine.

Installed this replacement some years ago on an ancient Yazoo 60 inch mower.
Has run like a champ every year til this one.

Began hesitating, surging, governor hunting, etc.
It is now to the point that I can start it, but it runs for about 5 seconds, then starves itself for fuel and dies.
I have the engine manual, and went through suggestions there.
I always start with the cheapest solution first, and progress to the most expensive. I'm sure most of the DIY folks out there do the same if they aren't sure what is the issue. blew out the fuel lines. cleaned out the fuel tanks. fresh fuel. new fuel filter. new air filter. new fuel lines. verified that the fuel pump is pumping fuel just fine to the carb inlet.

Fuel shutoff solenoid was suspect. Didn't always retract when current applied, so replaced that part, which was $125. New solenoid works fine, but didn't solve the problem. Checked all wiring for a short. none.

Removed carburetor, did a thorough cleaning, though it didn't look at all gummed or dirty, other than a few spots in the bowl. All orifices clear. After getting fuel back to the carb, it started after a couple of stumbles and idled beautifully. I gave it full throttle, and grinned like the cheshire cat when it roared to full life. I was happy. . .

Until I pulled it out of the garage, onto the yard to test the old girl out. Then the heifer died just like before, and I went to get the sledgehammer.

Please, if anyone knows why I'm having this frustration, and has a remedy for me to try, let me know. I'm to the point that I either send it into the pond, or haul it in to the repair shop and have a big 'ol bill to pay on a mower that is probably 30 years old.

Appreciate your help.
Doc Fixem

 

[RC Wells]

If it starts and runs when cold, then conks out when it is warm it is likely the CDI ignition unit. See if it is sparking when it conks out.

 

[Miccol]

Thanks for the tip, RC. Still had spark when it would shut down. I noticed something else. The longer I would let it sit between attempts to start it, the longer it would run before it would die. I figured there must still be blockage somewhere that was allowing fuel to seep into the bowl of the carb, but not allowing enough for it to continue to run. Since it ran great after I cleaned the carb last time, but died when I drove it out of the garage and into the yard to try it out, I thought maybe there was still something stuck in the carb, so I pulled it again last night. Did a more thorough cleaning this time, and now she runs like a champ. That's something to remember for all us folks. We get frustrated when stuff don't run. We would much rather be USING the equipment than WRENCHING on it. So we get in a hurry. If you're going to the trouble to pull the carb, grab a beer. Take your time. Make sure that baby is clean as a whistle before putting everything back together. Tested it out a couple rounds in the yard, but was getting dark. I was proud I finally got the sucker running. The wife was miffed that the yard looks goofy! Oh well. . .