Roo Man

My Feedback: (1)

I have 3 gallons of 5% fuel and want to use it. I currently run 10% in an OS46 on a Sig Senior Cadet, what kind of carb adjustment will I need to make for this change, leaner, richer, no chg?

Gary

1QwkSport2.5r

Going from 10% nitro down to 5% nitro will require a slightly leaner needle setting.

Roo Man

My Feedback: (1)

Thanks for the input, will try tomorrow.

Gary

JPMacG

My Feedback: (2)

Did you try it? What did you think? My experience with 2-strokes is that going from 10% to 5% makes no perceptible difference. I tune my engines every time I fly, so I would not have noticed a difference in the needle. But my engines seem to have just as much power and idle the same on 5 as 10.

Roo Man

My Feedback: (1)

Haven't had time due to illness and weather but will definitely try it next time at the field.

Gary

stuntflyr

I used 24 gallons of leftover C/L Stunt fuel from 5 to 15% nitro and all about 20-22% total oil and can say the OS 46 AX is a great running engine with a great ability to burn about any fuel you put in it. Afer all of that flying it sounds as if it could use bearings!
Chris...
PS I had a 46 SF that was the same way, it died in a horrible straight in due to learning about battery charging and its necessity.

iFrinkso

On the other hand, does raising nitro affect piston cylinder fit on these AX engines if you already performed breakin at lower nitro - or a lower average cyl temp?

Hobbsy

My Feedback: (102)

The piston to liner fit is self regulating, nitro changes won't effect anything any more than flying on a cool morning and then on a hot afternoon.