Frustrating Post-Idle Judder

[maxp]

As i open the throttle slowly, nothing happens til its about 20% open then it will jump from idle up to about 1450rpm.

If i keep the idle switch depressed as im opening it, it operates smoothly as you would expect.

Any ideas? Trying to creep up a hill was a pain in the arse as im either stalling it or ragging the clutch if i only want to go about 5mph.

[Alec]

Does it idle ok? Its only when gently depressing the throttle you get the problem?

[maxp]

Yep idles steadily on the button @ 850rpm.

It does this:
Throttle Amount Open , RPM:
0%, 850
5% 850
10% 850
15% 850
19% 850
20% 1350/1450 ish

Ive had the rubber intake boot off and the butterfly plate on the throttle body is definitely closed at 0%. And opens and shuts in line with what you would expect.

[loverdubber]

As i open the throttle slowly, nothing happens til its about 20% open then it will jump from idle up to about 1450rpm.

If i keep the idle switch depressed as im opening it, it operates smoothly as you would expect.

Any ideas? Trying to creep up a hill was a pain in the arse as im either stalling it or ragging the clutch if i only want to go about 5mph.

the idling switch sounds suspect there matey.

[Ben Lessani]

19% 850
20% 1350/1450 ish

I love the accuracy of how much you could pull the throttle - you should be an F1 driver with those skillz

[maxp]

I love the accuracy of how much you could pull the throttle - you should be an F1 driver with those skillz

Ive just had another gander and it looks like the revs jump up as soon as the throttle lever/arm thing stops touching the throttle switch. That kinda sounds like the switch is doing its job.

[Alec]

As i open the throttle slowly, nothing happens til its about 20% open then it will jump from idle up to about 1450rpm.

If i keep the idle switch depressed as im opening it, it operates smoothly as you would expect.

Any ideas? Trying to creep up a hill was a pain in the arse as im either stalling it or ragging the clutch if i only want to go about 5mph.

the idling switch sounds suspect there matey.

I would of thought idle switch aswell, as you say if you keep the switch depressed it revs normally. Dont quote me on it though bud

[rubjonny]

does sound like your idle switch is incorrectly adjusted. does the throttle hit the stop firmly? if you move the idle switch in too far it'll hold the throttle open.  Also check the cable isnt too tight, this is another reason the throttle can be too har open. if someone had the throttle too tight then adjusted the idle switch to suit, could explain it.

have you set it up as per my faq?