[Carigdon]

I’ve replaced all of the fuel lines, shut off, fuel filter, fuel pump, spark plug, air filter, gas cap. It starts and runs great for about 30 minutes then tries to die. I have to put the choke on to keep it running. After sitting in choke for a few minutes I can take it off and it will run great again for a couple minutes then tries to die again. It’s the same process over and over. I also rerouted the fuel line to avoid vapor lock. I know it still gets spark because it continues to run with the choke on. Does anyone know what the problem could be? Could it be the carburetor? I removed the fuel solenoid as well and bypassed it. Any help would be appreciated.

 

[Mark / Ohio]

Welcome to the forum!

 

[Carigdon]

I’ve replaced all of the fuel lines, shut off, fuel filter, fuel pump, spark plug, air filter, gas cap. It starts and runs great for about 30 minutes then tries to die. I have to put the choke on to keep it running. After sitting in choke for a few minutes I can take it off and it will run great again for a couple minutes then tries to die again. It’s the same process over and over. I also rerouted the fuel line to avoid vapor lock. I know it still gets spark because it continues to run with the choke on. Does anyone know what the problem could be? Could it be the carburetor? I removed the fuel solenoid as well and bypassed it. Any help would be appreciated.

 

[Mark / Ohio]

I moved this to small engines to see if anyone had any ideas. :fing32:

 

[Bill Kapaun]

I’ve replaced all of the fuel lines, shut off, fuel filter, fuel pump, spark plug, air filter, gas cap. It starts and runs great for about 30 minutes then tries to die. I have to put the choke on to keep it running. After sitting in choke for a few minutes I can take it off and it will run great again for a couple minutes then tries to die again. It’s the same process over and over. I also rerouted the fuel line to avoid vapor lock. I know it still gets spark because it continues to run with the choke on. Does anyone know what the problem could be? Could it be the carburetor? I removed the fuel solenoid as well and bypassed it. Any help would be appreciated.

When you apply choke, you restrict the amount of air entering the engine, which lowers the effective compression.
A spark plug might fire under those conditions and not with the choke off.
Get one of those cheap inline spark testers and install it.
Compare spark when first running and again when it starts showing the problem.

You may have a heat sensitive ignition coil/module.

 

[tomw0]

Do you have a fuel line(metal) routed above the cylinder inside the fan shroud/flywheel cover? A fuel pump? If you do, you may be running into vapor lock. The most wondrous fuel blends currently available seem to have low boiling points, or high vapor pressure, your choice. Kohler routed the metal fuel line through the shroud from the pump on the cam side to the carburetor on the opposite side. If you have a machine with a hood, it may be directing the expelled air from under the cylinder, warmed as it cools the cylinder & head, such that it gets fed back into the blower on the flywheel. The result is hotter than ambient air being used to cool the engine. See also: 'turbocool' ducting on some models.
I have found, and noted repeatedly, that if I remove the hood, run the engine for a few minutes, it will start to run properly as the fuel line cools and the hot fuel is replaced by cooler fuel. It does not die, but it is not running properly and smoothly, if I use it with the hood on during hot weather.
If you remove the hood and allow cooler air to the blower wheel, you may find you no longer have a problem.
Anecdote story over. Apparently I am the only one to have this circumstance. CV15S Craftsman 917.256580. New pump, new coil, new fuel filter.
tom

 

[Carigdon]

I removed the metal line and ran a new hose behind the motor to avoid vapor locking. I also put a new fuel pump on, but it keeps wanting to die after about 30 minutes.

 

[tomw0]

Perhaps some 'stuff' that's swishing around in the bottom of the fuel tank. It may finally get sucked to the outlet, form a semi-***, and restrict the flow?
The reported problem surely resembles lack of fuel, to me. Try a separate tank? Use a tiny-cam to view the inside?
tom

 

[Hipster]

I had the same issue, tried all that you have done. ALL Fuel lines, fuel pump, Chinese carb, spark plug.
Coil was the last part to replace.....and now it runs great. No dying, misfiring and I am happy.

 

[Cannon51]

I replaced the coil on a CV14 this week with one I got on Amazon for $15.99. Does your CV16 have the Smart Spark box?
Cannon

 

[Hipster]

Yes it does, I am glad the coil fixed it FINALLY!
Was very frustrating when it would work for 2 mornings then die after 1/3 of the way through the next time.