582 Idle Speed

[Byron]

Hi folks,

The idle speed seems to have crept up a bit on my 582. The manual states that the idle speed should be set to 2000 rpm. My motor is idling at about 2600rpm. I have never noticed it before, until this morning. The trike runs away with me in it. The choke and friction throttle were checked by the way.

Each carb has an idle screw that raises the slides. How does one set each one and ensure that the carbs are balanced? Is this something that must be done by an authorised person?

Could this be indicative of something else that is wrong? Engine temp seems normal.

Any advice?

[Dre'man]

Check you carb rubbers as well. Could be sucking air, If there was no mixture problems before then don't try alter settingss to compensate. Identify the problem first. If you can't see cracks on the rubbers pour some water over them.

[Byron]

Hi Dre'man,

The rubbers were replaced recently and are still soft. Not a single crack evident...... but I will check that they are secured properly. Thanks.

[Morph]

Take the airfilters off so you can see the pistons inside the carbs.

There are two big screws on the sides of each carb. (they are the ones with the springs on them). Screw these out until the pistons are at the absolute bottom of the carb. (make sure the throttle cable is not keeping them from closing all the way. If so loosen the lock nut at the top of the carb where the cable enters the carb, and screw the screw in.

Now take two long drinking straws and insert them into each carb, place each tip underneath the curved bottom of the piston. In other words the straw will be sticking out of the carb, held in place by the piston.

Now start turning each screw in slowly and watch the straw. As soon as the screw makes contact with the piston it begins to move up and the outside straw tip will move down.get both carbs to this point when the straw first starts to move.

Now note the position of the slot in each screw. Screw each screw in 1.5 turns.

Start the plane and check the idle. If too high turn each screw out the same distance, and vice versa if too low.

The engine should idle at 1800 to 2000 rpm.

Set the rest of the settings as explained here

http://microlighters.co.za/viewtopic.php?t=6514

[Bacardi]

On your foot throttle lever, there is a shrink sleeve tip supposed to prevent the throttle cable end from protruding through and exiting the tube locating it to the lever. Mine (rubber thingie) was missing and when I used the friction throttle during flight, the cable end sticking through the tube did not retract fully back into the tube due to the copper stopper on the cable end hooking on the side edge of the tube. I got about 3000rpm due to this, once had to throw mags upon landing at Brits and it took me a quite some time to trace this. Very easily overlooked.

[Byron]

Thanks Morph.

Your explanation makes sense. I'll try it out tomorrow morning.

[Byron]

Hi Bacardi,

That was the first thing I checked. Not the case though, but thanks anyway.