Husqvarna 435 idle issue

[Sbridger11]

I have a 435ii that was failing to start. I replaced the ignition module and now it starts fine. However it now appears not to come off fast idle. The usual blipping the throttle after start doesn't reduce the idle speed and the chain runs quite fast when I take the brake off. As the saw warms up the idle speed drops so the chain just creeps forward, but doesn't stop. I think it is a fast idle issue as the T screw is as far clockwise as it will go and adjusting the L screw doesn't make much difference. I can't see the ignition module having any impact on idle speed? Any ideas would be appreciated.

[adw]

Read my post on the correct ignition units and flywheels for these models

[Sbridger11]

I did indeed and that helped me to ensure that I ordered the correct one.

[adw]

The idle screw should be turned anti clockwise to reduce the rpm.

[Sbridger11]

Llet me double check that. Thanks

[spudulike]

If the idle screw is turned fully in, it is no surprise turning the L screw has little effect. Probably best to set the L screw to around 2.5 turns out...I believe this is correct and then set the idle speed so the engine keeps running and the chain doesn't spin.

[Sbridger11]

Thanks all,
A quick check is confirming that the idle T screw is fully clockwise (this was as from new).
I do remember turning anticlockwise for a numbers of turn with no difference, then the idle speed increased which  is why I (incorrectly) assumed that clockwise was slower.

I most likely won't have time to have another go until the weekend.
ADW FYI the ignition module I fitted is a newer revision than originally fitted, but still compatible as per your chart.
579 63 88-05  vs 579 63 88-02

[adw]

The idle screw is conical on the tip, so as you screw it in or out it acts on the the throttle shaft quadrant, so theoretically if you screw it out fully the throttle flap will be completely shut and the engine will stop, if it does not then either the throttle shaft or throttle flap is jammed for some reason, so turn it manually and see if the revs die, if not you may have an air leak.

[spudulike]

7 hours ago, adw said:

The idle screw is conical on the tip, so as you screw it in or out it acts on the the throttle shaft quadrant, so theoretically if you screw it out fully the throttle flap will be completely shut and the engine will stop, if it does not then either the throttle shaft or throttle flap is jammed for some reason, so turn it manually and see if the revs die, if not you may have an air leak.

Very good, you will go far in life.......if fixing 2 strokes......nice tip on if the idle screw is almost completely out and the engine keeps running you may have an air leak!!

[Sbridger11]

All sorted, thanks for the guidance. It needed a lot of turns backing off the T screw.
Definitely a case of  RTFM PROPERLY combined with lack of experience.