the idle mixture screw on our 400 gas does not affect the idle at all. it runs fine, you can drop it down to about 300 rpm if you want. However, it idles pretty smoky, smells bad too. If you try to start it at lowest throttle even when speed set correctly to about 450, it will overchoke and flood. Also, if you partially remove idle mixture screw, the tractor all of a sudden will idle fast. But, if you completely remove screw it will die.
This was a running tractor (always hard starting, rich idle, throttling up even one notch when cold would kill it). I partially disassembled the carb to check float adjustment and other things, and then synchonize governor/carb. I suppose it is a passage i didn't make time to ream out, but which one? I think it is the correct carb for the tractor, the main discharge jet is removed with a nut inside the bowl vs. a screw head on the outside.
thanks for your input.
karl f
ps i found one float set higher than the other.
This was a running tractor (always hard starting, rich idle, throttling up even one notch when cold would kill it). I partially disassembled the carb to check float adjustment and other things, and then synchonize governor/carb. I suppose it is a passage i didn't make time to ream out, but which one? I think it is the correct carb for the tractor, the main discharge jet is removed with a nut inside the bowl vs. a screw head on the outside.
thanks for your input.
karl f
ps i found one float set higher than the other.