base idle

[Tri2Tri]

Due to the idle jumping around and stalling at roundabouts ect once you lift the throttle I decided to clean the stepper motor. This had heavy sooty deposits and looked like it had never been cleaned. While the stepper motor was out I thought i would check the base idle. This is what I did, is this correct.
I blocked off the stepper motor hole in the plenum. Turned engine over which idled at 2,200 revs. I tried to adjust the idle screw on the plenum but it was screwed right down. I tok the idle screw out and cleaned up the screw and also were the screw sits. There was a lot of black sludge. I put the idle screw back in and started the engine...reved around 2,800 revs. As i screwed the idle in it took a while before this effected the revs and only the last part of the screwing in had any effect which made the idle sit back at 2,200 revs....this was with the screw fully screwed down.
I replaced the stepper motor and turned the engine over. revs settled at 900rpm.
Now this is fine but im confused as to why my base idle is so high???? Was I checking this wrong?

[Tri2Tri]

Ahhhh. Thanks Carsy. I will have another go tomorrow. Cheers.

[Tri2Tri]

Right I'm off to have another go as no doubt messed up the base idle not knowing what i was doing in the first place. I now understand about blocking off the pipe but to re check the idle would i need to remove the stepper motor again and block up the hole or could i just disconect the wiring and leave the stepper motor in situ.

[Tri2Tri]

All sorted, thanks guys. Base idle would not keep engine ticking over. Re adjusted to 600rpm now running good and stable at 900rmp once stepper feed pipe is released.