K301 help needed

[Rideawaysenior 25]

Okay, here is a stumper. I've got a K301 newly rebuilt block. The carb was rebuilt by me and I've done dozens with no problem that work fine. I did this one to spec as well. The problem is, the engine will start and run, throttle up and idle great for about five minutes. Then the engine will slow on idle and then stall. Sometimes it will start again and then there are times that it won't. The float is set to spec, the jets are set to spec, the fuel pump is good and the valves are not sticking.

What is my problem? Could I just have a junk carb? :)

[multihobbyguy 35]

I had a coil that would do that to me on a Cub Cadet. It would start and run but it would heat up and quit on me. I have no idea why it happened but when I swapped it with another tractor the problem moved to the other tractor. Just my own experience, although it seems you think you may have a fuel problem. Do you have a fuel line collapsing on you?

[Rideawaysenior 25]

Nope, new fuel line. Engine is on a mount and the fuel line is submerged in a full gallon can.

[Anglo Traction 761]

Never doubt your own work. Accuracy is no Accident !. I agree , my money is on the iffy HT Coil .

[Kelly 1,033]

First you need to figure out if it is a fuel or spark problem?? then troubleshoot from there, check for spark with the no start issue, if you have spark give it a small shot of carb cleaner to see if it will fire.

[Dale 0]

check the main jet needle make sure the little holes are open

[Rideawaysenior 25]

Needle is super clean. I snaked the jets as well as the holes in the needle with some thin wire. Just a standard practice for me when rebuilding a carb. I guess I'll try a coil. I've got a couple kicking around.

[Dale 0]

is your vent open on gas cap

[Duff 206]

is your vent open on gas cap

Dale, I think he's working from a test mount and just pulling out of a one gallon portable tank. Good thought on the tank vent, though, as that's certainly been known to cause a similar problem on tractors.

~Duff :)