Kohler K341 16HP quits when it gets hot.

[Lake Delhi 2]

I have a C160 with a Kohler K341 16HP.  After around 45 minutes of use the engine starts back firing and it dies. I let it cool off and it runs just fine. So far I have replaced the coil and condenser and it still quits. I'm assuming that maybe something in the electrical system is drawing too much current and causing the coil to open up? Maybe the points, ignition switch, ammeter, rectifier, or a safety switch? 

 

Thanks, Tyler

Edited May 25, 2020 by Lake Delhi

[peter lena 9,093]

check out your fuse area for corrosion , get some DIELECTRIC GREASE , AND CLEAN OFF ALL YOUR ELECTRICAL SLIDE ONS. i use some fine sandpaper to clean off the flat slide in , and grease it , not heavily just enough to enhance conductivity , you also might have an electrical grounding short . look over all your wiring lay out , for fraying or corrosion. let us know what you find , good luck , pete

[pfrederi 18,343]

Welcome.  Make sure the vent in you r gas cap is clear.  Try running it with the cap a bit loose.  Vacuum can build up as tank empties and the pump cannot over come it.

[gwest_ca-(File Mod) 11,252]

Have a test light or voltmeter?

The second it quits see if you have voltage at the coil (+) positive terminal with the key in the RUN position.

Condenser is wired to the coil (-) terminal?

The body of the condenser must be grounded to the chassis. If it is sitting on fresh paint the ground may be compromised.

 

If you find power at the coil it may be fuel related. If the gas cap vented? Loosen it off to check.

 

Garry

[squonk 42,587]

I'm thinkin vapor lock. Does this tractor have the stock muffler?  The heat from it may be boiling the fuel in the fuel pump.

[edgro 679]

Check screen on fuel tank fitting

 

[ZXT 2,401]

What coil did you put on it? Does it have an internal resistor? If it doesn't, you need a ballast resistor in line or install the correct coil. 

 

The issue is likely fuel related, but I mention the internal/external resistor coil differences just in case you put the wrong one on. Could make finding the real issue more difficult.

[JJMason84 3]

I am having the same problem but it does not backfire, just shuts down when it gets hot , about 2hrs of working it with the loader. When cooled it runs just fine. Replaced the coil, still does it. Going to replace the condenser today to see if that works. But I will try the gas cap, 

[Tuneup 1,433]

ZXT is right - be sure that the coil you now have has the internal resistor or it will overheat.

[hotajax 226]

Interesting topic.   What is an internal resistor as it relates to the coil?  I am not familiar with this.  Thanks. 

[hotajax 226]

On 5/25/2020 at 1:25 PM, edgro said:

Check screen on fuel tank fitting

 

I had the same problem.  Made me crazy.  Turned out to be the little screen inside the tank, on the very bottom.  Quick to check - just pull out that grommet and have a look. You'd be surprised how much debris you never see gets in the tank over time. In fact, I know of a guy who takes his tank off every so often, and washes it out with water and detergent just to keep it clean.  Good luck.

Edited May 29, 2020 by hotajax
Add info

[ZXT 2,401]

3 hours ago, hotajax said:

Interesting topic.   What is an internal resistor as it relates to the coil?  I am not familiar with this.  Thanks. 

Ignition coils run off of approx. 6v as opposed to 12v. The resistor drops the voltage down. If you have a coil that requires an external resistor and you don't install one in line, it will have 12v to it full time which will cause it to get extremely hot and break down. An internal resistor coil has the resistor built into the coil, so all you have to do is hook 12v to it and go. Internal resistor coils are what came as original equipment on these tractors. 

Edited May 29, 2020 by ZXT

[hotajax 226]

17 hours ago, ZXT said:

Ignition coils run off of approx. 6v as opposed to 12v. The resistor drops the voltage down. If you have a coil that requires an external resistor and you don't install one in line, it will have 12v to it full time which will cause it to get extremely hot and break down. An internal resistor coil has the resistor built into the coil, so all you have to do is hook 12v to it and go. Internal resistor coils are what came as original equipment on these tractors. 

Good to know, thanks for the explanation.

[hotajax 226]

23 minutes ago, hotajax said:

Good to know, thanks for the explanation.

So these days, I only have one vehicle that requires a big coil, and that is my Wheel Horse.

[ZXT 2,401]

4 hours ago, hotajax said:

So these days, I only have one vehicle that requires a big coil, and that is my Wheel Horse.

I've got about a dozen cars that still use them. My Mopars have a external resistor coil with a ballast resistor. My GM cars have a resistor wire that serves the same purpose. Don't have anything other than a WH that has an internal resistor coil.

[WHNJ701 4,165]

my 854 used to do something similar, after changing and checking the obvious parts it still did it.  after I fully rewired the tractor with fresh copper the problem went away. after wards looking at the old wire it was very brittle and had corrosion