582 smoother idle!?

[Olle1975]

Hello,

has anybody an idea for a smoother idle?
My engine is shaking at 2000 rpm, by 2800-3000 rpm or more it runs very smooth. Has anybody else this situation or a idea to get smoother, may be changing Idle jet?

Olaf

[Dusty]

First thing is to check your rpm is correct ,the factory tachometer is only a general guide!
Sync your carbs, preferably using the vacuum test.
I run 35 idle jets and have a smoother idle than the 55's
Warmup is still best around 2500rpm but when warm 2000 is ok
The box will start to growl around 1700!
Your idle stop screws may end up screwed right out,so check the throttle slides aren't left hanging(they should both give a dull thunk noise when closed)
You will also notice your EGT'swill be better on finals around 950 rather than flatlined off he scale,it's good to know there is a healthy fire up front if full power is needed in a hurry!

[Av8r_Sed]

What prop are you using? If it has a high mass moment of inertia it'll be tough to get it idling smoothly.

[Olle1975]

Thanks for comments!

I additionally use Tiny Tach for rpm.
The carbs are sync mechanic and pneumatic.
I use the GSC prop, it's not older than 2 years with round about 120hrs.

I run 35 idle jets and have a smoother idle than the 55's
Is the 35 idle smaller than the 55 and the Idle gets leaner? I suspect the idle has to get richer for smoother idle?

You will also notice your EGT'swill be better on finals around 950 rather than flatlined off he scale,it's good to know there is a healthy fire up front if full power is needed in a hurry!
How do you hold up your EGT during Idle in final?

Olaf

[Dusty]

Leaner for a smoother idle and higher EGT.
Rotax seems to set rich at idle, possibly to minimise the risk of getting lean if the prop is driven on descent.
This doesn't seem to be a problem with a 582 in a kitfox but maybe in another application this may change.
Be aware on your first few flights 1200EGT game over!
Also bear in mind an oil injected engine will be getting oil on a lean descent,
Premix will need some oil,so occasional throttle will be prudent

[napierm]

2nd that on the idle jets. I ran the #45 idle jets on the 582. That's with a 3-blade GSC prop on a 3:1 "C" gearbox. Engine would load up and quit on final before that. Same with extended idle on ground. Another help was switching to the iridium tipped spark plugs. The fine wire runs hotter and doesn't foul easily.