I'm helping a buddy with his FOX 3.2 engine and we are having a problem adjusting the low end. If we move the throttle from idle to about 1/3 quickly the engine will simply stop. If we bring the throttle back to idle or to about 3/4 full the engine continues to run. We've tried to richen the low end screw by turn it out CCW a little at a time. It's now a total of 4 turns (4 1/2 it falls out) and it still is not transitioning. We have been able to adjust the high end with results, but we did back it off to about 1 1/2 turns until we got the low end set. We have run about 1 gallon of fuel through the engine. Does anyone have any idea what we should do next?

TIA,
Scott

once you get the high end set don't back off the high speed needle to set the low end. How old is this engine? Is this the first attemt at running it? Do you have carb filters in place? I would guess that if you can't get it rich on the low end you have something blocking the flow.

The engine is brand new. We have run about 8 tanks of fuel. 3 in the the air. I did try setting the low after setting the high, with the same bad result. I just had reset the high end back to the starting point after trying everything else. My understanding is you need to set the high rich, then set the low, then set the high to a leaner setting. Then maybe go back the low again. They both kind of chase each other.

The ballpark settings for that size engine are 1.5 to 1.75 open on the low and 1 on the high. Remember that the engine always sucks from the low needle so if it wont transition from this base setting and your ending up with the low 4 turns open you've got a problem. Either you have a fuel blockage or if the carb is old the diaphrams dry out. If the carb if fairly new clean it out with compressed air but if its old I would put a carb kit through it before you bury it.

It is new. I figured it must be clogged or something is leaking somewhere. How do I clean it out with compressed air. Do I just shoot the air into the carb opening or do I remove the fuel line and shoot it into there. Sorry for asking such a basic question, but I've not worked on small gas engines much....

whoa!
first make sure you have not accidentally got the throttle plate rotating thewrong direction!
If you removed the throttle plate stops -this can happen.
the throttle plate stops just next to the low speed discharge hole - then - that edge swings back , across the high speed hole as it fully opens -
If reversed - this transition does not happen correctly - tho the engine will run -sorta -
As noted above - get the engine running FIRST , using the low speed needle - then slowly open the throttle and adjust the interaction of the low and high -
Unless something is buggered - about 1.5 turns is good start on each needle.