needle settings in cold weather
 

High Speed Needle Setting

Just wondering what to expect when I go at it soon in low 50's (F) with my BVW .82 on Wildcat 10%

Last time I flew (october) it was 90+ (F)

Will it need to be richer/leaner?

Thanks in advance!

Smitty

Richen it up!
 

Always start your df engines on the rich side. If they havent been run for a while or are in a different climate richen it up 1/2 turn. A BVM engine will run poorly rich but won't run very long lean. By poorly i mean low max RPM.

I always richen my engines needle before a first start of the day. Make sure to let it idle until heat is comming out of the glow plug hole. (every time!) This means it has lubrication and is up to working temp. This gives you a chance to hear the engine. Never start it and immediatly go to wide open!

Keep it rich! Remember to have good smoke.
Dustin

needle settings in cold weather
 

Smitty,
the colder the air is, the denser the air is. Translation, there is more oxygen per cubic cm or foot. So if there is more oxygen, you must add more fuel. Richen on cold, and lean on hot days.

BTW, dont just arbitrarily richen and lean, do was Dustin said by richening it up first and then slowly lean towards max rpms. Once at max rpm richen it up about 500 rpm. (500 is only good if you have an in-flight mixture control so you can continue to richen throughout flight) Do this with a tachometer and before the first flight of the day. This way it wont matter if it is hot or cold outside, your engine will always be properly set. Although it will make more power on cold days. This should yield good results.