1991 400 se tickover again

[beduch]

Yes I am sure by pass tube is blocked and I have checked for leaks also tube under stepper motor is ok
No one has reset throttle stop lately
I have just reduced tickover by adjusting throttle stop screw idle now 1000rpm not sure what it should be
If I take off pipe to stepper motor with engine running it has no effect on tickover

[2 sheds]

Yes I am sure by pass tube is blocked and I have checked for leaks also tube under stepper motor is ok
No one has reset throttle stop lately
I have just reduced tickover by adjusting throttle stop screw idle now 1000rpm not sure what it should be
If I take off pipe to stepper motor with engine running it has no effect on tickover

With stepper blocked should be 575 rpm. will it go that low ? if not the butterfly is too far open or the throttle by-pass screw is letting air past, you can check this by taping over the hole (inside throttle opening). 1000 is still too high as the stepper likes to control the idle.
tim