I have a DF 70 with a throttle adjustment problem. The motor goes into gear just fine, but I need to advance the throttle at least 2 maybe 3 inches before I get any movement on the throttle linkage on the engine. I'm able to get the rated RPMs at WOT, and when I pull back on the throttle, I dont reach Idle until I'm almost at the the stop. Its as if there is a lot of lost motion inside the throttle housing going from idle on up, but none going back down. BTW this also occurs when going into reverse. I have 2 large screws with locking nuts on the top of the throttle, but I see no other adjustment.
