I'm dealing with a hanging idle problem right now - ended my ride pretty much right after I started today because it was dangerous in the woods. Came home, pulled the 45 pilot and put in a 48 thinking maybe a lean issue. Didn't get a chance to go back out, but in the garage, it still did it once. And when it hangs up, it hangs up at 6000 rpm, occassionally less, so that's not cool. A light blip will generally being it back down. Been intermittent since I had the carb off to clean in July. No air leaks that I can find and the slide is not hanging up visually with throttle movement. I'm guessing it's crappy fuel screw tuning on my part. I have zero bog, good All around power, and it starts perfectly cold or hot. Annoying. Why haven't I bought a 450FX yet...
Lot's of issues can contribute to hanging idle, usually it's not throttle/mechanical.
Here are the most common I know of:
- fuel screw lean
- fuel screw adjustment started with the idle way too high
- fuel screw oring torn or missing
- pilot is too small (45 is nearly 100% of the time the correct size)
- pilot jet is visually clean, but corroded inside - needs to be new
- pilot passage above jet has corrosion, leaning out the pilot. Must be soaked in solvent and reamed with wire or fishing line
- loose or cracked air boots
- slide plate seal is bad
- worn out slide bore; wheel grooves put the slide in the wrong place
Edited by Krannie McKranface, October 10, 2016 - 07:27 PM.