proper Idle for 582

[Jon 2]

I got such good advice on my last question I have another.

I am setting up my 582 on my Avid  Mark IV and doing the break in time.  I had one person say it should idle at about 2000.  Another said to have it set lower. (What I mean is that when you pull power is stops at 2000).   He said if you are at 2000 setting up for a landing you may still have to much thrust and land hot.  He also stated that a 2000 setting or a little above is better for the C drive but you need the capability to pull RPM below 2000.

So what should the bottom RPM idle be 1200, 1500 or ??.

The main jet has been replaced due to altitude and the jet needle set on the third groove and it seems to run good above 2500 RPM but around 2000 not as good.  Is the idle jet adjustable?  I don't see much about adjusting just a bunch of different ones to select.for replacement.  If it is adjustable does going in make it more lean or more rich (it looks like going in would make it more lean).  If it is replacement are there charts on how to select the correct one. 

Thanks

Jon

[1avidflyer 1983]

Unless you have a clutch, you will have the gears banging around if you are idleing below 2500 or so.  Don't think you can idle it down to around 1500 very easy.  Remember, your prop will only be turning 1/3 the speed of the engine if you have a 3 - 1 gearbox, at 833 rpm, ( 1/3 of 2500 engine rpm) the prop wont be pulling to very hard.   Jim Chuk

[EDMO 1078]

I'm jumping in here not knowing about your engine, but if I was at your altitude I would be reading all the posts about the Hackman install.  I noted to, that you were asking more questions about adjusting your carbs, and I cant answer that.

EDMO

Edited 8 Dec 2015 by EDMO

[thebriman 69]

I set my idle stops at about 2200 rpm. That being said I never let it idle below about 2600 on the ground so as to keep the gearbox from chattering.  even a slow power off approach with the throttle pulled back to the stops gives an engine rpm of around 3000 to 3300 because of the windmilling of the prop.  Never had an issue with these settings

[Dusty 126]

Ground vs air idling is a often debated point,even with 35 idle jets and the idle stop screws all the way back I car get much below 1800 rpm but a little rough below 2400 

approach rpm tends to sit around 3000 and on rollout requires additional throttle to stop chatter,slower idle speed gives a slightly steeper approach but has little effect on landing speed.

remember on finals stick controls airspeed,throttle decent rate

[ChrisBolkan 130]

I always set ground idle to around 1800 RPM. This would typically be a bit rough and rattle the gearbox a little. However, I never actually idled the plane at 1800. I always idled at the lowest RPM that the engine would run smooth. Depending on temperature, humidity and pressure that RPM would vary a lot, so I just set it for smooth. Usually that was somewhere between 2500 and 3000 rpm. If I wanted absolute minimum thrust while landing, I would pull the throttle back to idle stop during landing, but the air would windmill the prop faster than 1800 so the engine rarely actually saw 1800 or ran rough. Immediately upon landing I would run idle back up to smooth. I suppose there are a million ways to skin this cat!

[Knuckledragger 135]

I always set ground idle to around 1800 RPM. This would typically be a bit rough and rattle the gearbox a little. However, I never actually idled the plane at 1800. I always idled at the lowest RPM that the engine would run smooth. Depending on temperature, humidity and pressure that RPM would vary a lot, so I just set it for smooth. Usually that was somewhere between 2500 and 3000 rpm. If I wanted absolute minimum thrust while landing, I would pull the throttle back to idle stop during landing, but the air would windmill the prop faster than 1800 so the engine rarely actually saw 1800 or ran rough. Immediately upon landing I would run idle back up to smooth. I suppose there are a million ways to skin this cat!

This describes exactly how I'm set up and operate.