Engine stalls after 30 minutes: PLEASE ADVISE!!

[Danny Wolfe]

Yes guys, i have that some ole thing that others have experienced with my CC 2166 with a Kohler 16 HP stalling after mowing for 30 minutes...This happened last year too and i thought i had it fixed by replacing the COIL. However, this time, it starts sputtering instead of just suddenly dying, and i can pull the choke and keep it running with full choke. it eventually clears up and i disengage the choke and continue mowing..until it happens again. I thought it may be a failing fuel pump or trash in the carb. The plug is new and looks perfect. I have checked the fuel solenoid on the carb, and it works fine. I have removed the carb and it appears pristine clean. I Drained all the fuel and made sure the tank was clean...i didn't find any trash or grit in it. I have a bad muffler and wondering it that could cause this issue? I plan to replace the fuel hoses tomorrow, and put it back together. ANY IDEAS GUYS?? I am lost! THANKS in ADVANCE FOR YOUR ADVICE AND FOR SHARING YOUR KNOWLEDGE!!

[R Bedell]

Definitely a fuel or Carb issue.

I don't know for sure, but as a suggestion, is the Fuel Cap properly vented...???

[Danny Wolfe]

THanks for the reply! Yes, i checked that as well today. I don't really know how to test the fuel pump, or how to know if i am getting a good GAS FLOW. OR how to know if i have a bad coil again....this oem genuine Kohler part only has about 20 hours on it.

[Sam Mac]

If it was my tractor I would pull the fender pan, clean the 20 something year old mess, pull the tank and flush it out, replace all the fuel lines from the tank to the carb, new fuel filter and fuel pump.

KH-12-559-01 Kit, Fuel Pump
https://www.google.com/search?ei=YzY....0.du1qUmFgs_o

[bugeye]

My Cubs have Kohler Commands with a crankcase pressure pulse fuel pump. Not sure what fuel pump you may have on your tractor. I would have intermittent fuel starvation when on a slight slope with less than half a tank of fuel. Not predictable or repeatable. I replaced the fuel pump and all is well. The fuel pump I removed was the flat square metal with layered segments. When disassembled, the rubber check valve flaps appeared worn and out of place. I sourced the new fuel pump on Amazon.

O, and listen to Sam. I had lots of dirt in the fuel tank.

[ol'George]

If pulling the choke helps, that tells me it is a fuel delivery issue, not electrical.
You said you drained the tank.
Did you remove it and flush thoroughly?
Lint and fine foreign matter are not visible through the fill neck.
Also remove the fuel line @ the carb and crank it over, it should produce pulses of fuel, not just a weak stream/dribble.
Also there can be a clog just above the needle valve in the carb inlet hose barb or elbow, if so equipped.
---just some additional things to check.

[cooperino]

The OP said in first post he drained and cleaned the tank. If this is only happening after running 20 min then I would tend to think fuel pump. After it gets hot it could be malfunctioning. By pulling the choke he is using vacuum from running engine to pull fuel through the weak pump.. Just my thought, not stating this is a fact.

[Danny Wolfe]

Thanks for all your advice! I replaced the fuel pump, cleaned the carb again, replaced air filter, and fuel hose all the way to the carb. SO FAR, SO GOOD. I also removed the muffler and had the hole welded. It runs much quieter and hopefully the exhaust not blowing heat on the frame rail and possibly causing vapor lock is a successful repair. I will find out this weekend! I was amazed at how long it took fuel to reach the carb. I cranked on it for a WHILE before i got gas! LOL....

[Sam Mac]

Yep on a 2000 series I have had to put a little pressure to the tank to push the gas up to the fuel pump or squirt same gas into the carb to get then going.

[Steve N Mi]

Originally Posted by ol'George

You said you drained the tank.
Did you remove it and flush thoroughly?
Lint and fine foreign matter are not visible through the fill neck.

Flush thorougly with what? More gas or carb cleaner ...? Is there a residue likely from gasoline dyes etc. that need a chemical added to get rid of?

FWIW, I have seen a metal shutoff valve like those used at the tank bottom become so rusted inside that they will no longer allow gasoline to pass through as it should. I suspect the 1872 I'm working on now may be suffering from this. I need to investigate further before saying for sure.