[Darren Kerns]

Guys,
I have a question. When I start my RV8 I can pull the throttle all the way back to idle and I will get 680 on Vision Microsystems. When I come in to land, it seems I cannot get it below 800. Even on the roll out and stopping with my brakes, I still cannot get it back below 700 rpm. I have an Aerosport 200 hp with Hartzell CS prop. Someone told me to turn down a screw that adjusts the idle. Is this correct? I am not complaining because I am making of my best landings yet. (Wheelies)!!
Thanks guys,
Darren Kerns
RV8 N214TK

 

[Kahuna]

Your engine model style and size is not relevant.
Your approach decent rate will dictate how much air is pushing the prop to increase the RPM. If your moving fwd at all the prop is increasing RPM.
A cold start rpm is also not relevant.
Yes its OK to turn the throttle stop screw to decrease approach RPM.
After doing so, often you will need to crack the throttle just to keep the engine from stalling while taxiing. Its a personal preference. Sounds like your preference already is to lower it. By all means do so. Drop it a cold static 100rpm and and go try it.
Best,

 

[Geico266]

Great information Kahuna.

Also, it is important to see how much fuel is burning (GPH) at idle, depending on engine size. Any rule of thumb on idle fuel burn?

 

[bfilarsky]

A cold start rpm is also not relevant.

Obviously while he is moving, the propeller will turn faster due to windmilling. Why after he stops though? It seems that the engine may have less friction when its warmed up and all the parts are at operating temperature and the oil isn't so thick? Seems reasonable to me, and now that I think about it, I believe the Cherokee I fly does the same thing. I dunno, just taking a shot in the dark here.