1996 DT4 won't stay running

[tonyiiiafl]

hello all! new member here with a couple of questions. I just bought a 1996 DT4HP. It was said to not stay running. The gas and carb looked pretty gross, so I cleaned out the fuel system (changed the small screen in the shut off valve, changed inline fuel filter, and disconnected the fuel line while pulling the starter cord and had PLENTY of pulses of gas shoot out.) I tried to clean the carb but it was a mess, so I bought a new one and installed. Same thing. I choke and pull the cord and it sputters to life, but chugs as I reduce the choke. Then it just dies. The longest I have been able to keep it running is around 10 to 15 seconds, and even at that, it is just chugging at low rpm. As I said, gas pump appears to be good, fresh filters and new carb.

ANY advice that I can hear or have I missed something??

Thanks in advance for the help!

[Solarman]

OK. Do you pre-mix oil and gas? The new carb you put on? Did you adjust the air mix screw, or the idle stop screw? What is the setting of the idle air-mix screw ( # turns closed, till lightly seated)? The setting should be in the manual, what does the manual say to set it at (it should be somewhere between .75 [3/4] to 1.5 [1-1/2] turns open from lightly seated - never over tighten). This screw only adjusts the amount of air that mixes with the factory preset amount of fuel at idle. So opening it more adds more air mixture (leaner running), and closing this screw reduces air mixture (richer running).

The idle stop screw prevents the carb from going too slow. So it should be set just about 1 - 2 turns in from where the butterfly rests, and can be adjusted more, or less, according to the idle rpms, once motor is running properly.

When running above idle speed, these two screws do not affect the operation/speed of the motor, only at idle.

Good luck, post back when able of how you're doing.