Ed_Wischmeyer
Well Known Member
As I've been teaching myself to fly my new (to me) RV-9A, I've noticed a few peculiarities, like, with full flaps (32 degrees) and idle power, the airplane only descends at 500 feet per minute. Sure, it's clean and has a big wing, but... And when I land on a long runway in the touchdown zone and let it roll out, 5,000 feet later the plane has only slowed to 38 knots. Takes lots of braking to slow her down.
Yup, it's the idle speed. Or was. Cold, the engine idled at 700 RPM, but warmed up, the idle was more like 950. The idle mixture was too lean because there was no RPM gain pulling the mixture back to cutoff. And there was a jam nut missing on the idle adjustment clevis at the carb.
A friend fixed all those for me yesterday, and the RV-9A now should fly a whole lot more like an airplane. The idle speed (warm) is now 550 RPM with a 40 RPM increase when the mixture is pulled back to idle cutoff. Need to get over the last symptoms of this stupid bronchitis before I go try it, though.
The RV-8 has the same out of adjustment symptoms, but with the short wing and constant speed prop, it has no problems descending like a brick when I ask it to.
With a new (to you) homebuilt, you always need to be careful about everything, and I've found some electrical quirks in the new bird -- but I wasn't expecting to find anything as generic as the carb being misadjusted. Or maladjusted, perhaps...
Yup, it's the idle speed. Or was. Cold, the engine idled at 700 RPM, but warmed up, the idle was more like 950. The idle mixture was too lean because there was no RPM gain pulling the mixture back to cutoff. And there was a jam nut missing on the idle adjustment clevis at the carb.
A friend fixed all those for me yesterday, and the RV-9A now should fly a whole lot more like an airplane. The idle speed (warm) is now 550 RPM with a 40 RPM increase when the mixture is pulled back to idle cutoff. Need to get over the last symptoms of this stupid bronchitis before I go try it, though.
The RV-8 has the same out of adjustment symptoms, but with the short wing and constant speed prop, it has no problems descending like a brick when I ask it to.
With a new (to you) homebuilt, you always need to be careful about everything, and I've found some electrical quirks in the new bird -- but I wasn't expecting to find anything as generic as the carb being misadjusted. Or maladjusted, perhaps...