How big of an airplane will a Brodak .25 pull

[frank mccune]

     Hi All:

     I have a Brodak .25 on a 480sq. in. profile stunt plane Sig? that weighs 44 oz.  Will the .25 have enough power to fly the pattern?

     I had this engine on a Super Clown and it had a large amount of power for that smaller airplane/

     What prop should I use? I plan to run the engine in a wet 2 cycle.
             
                                                                                                                                                                          Tia,

                                                                                                                                                                          Frank McCune

[Motorman]

I have a B25 on a Brodak Shoestring (395 sq) and it flys ok but I had to drill out the venturi a little and use a 9-4 prop. That engine doesn't have allot of power, I wouldn't put it on anything bigger.


MM

[john e. holliday]

In my experience, the Brodak .25 stock does not the umph of an LA 25 until you do as stated, put in a larger venturi.  Of course that means more fuel also, but the stock B25 are fuel misers.   I have run 10-4,  9-5&9-6 props on them.  Another thing is you may have to go shorter lines.    Just finished reading the Stunt News article on trimming and have to agree that some people fly too slow or too long a lines for a set up.   I like to fly a plane where it is happy.   Set the needle where the engine is happy with a prop and trim the plane.   After reading the article I have come to the conclusion that it takes two people to trim a plane.  I myself can't tell if the plane is straight from in the center of the circle.   

[phil c]

John, the precise way to discover if the plane is straight is to do inside and outside loops. Trying to decide flying level can be very tricky, especially from inside the circle.  Start large and easy loops and then tighten them up.  If the plane has any significant warps the lines will get light turning one direction but not the other.  Getting light on insides means it's rolling left.  Light on outsides it's rolling right.  Once the plane is flying evenly you'll be able to pull several very tight loops in either direction and the plane will not get light in either direction.

Watch out for wind.  Doing loops to far into the wind can up a significant glitch in the loop in the upper windward quadrant.