ryobi 25cc question

[perce]

hi from australia,i have just converted a ryobi weed wacker 25cc ,i had intended building a big john bi plane which goes back many years its a 76 inch wing span which alot of the flyers used to fly with a 60 to 90 size 2 stroke,do you think i am going to big for the motor if so i can have the plan reduced,the other question is what prop should i start with,thanking you for your advise. perce

[twilightflyer]

I converted the same engine and flew a 'Cloudhopper' with it, that being 100" wingspan, that has an open fuz construction made mainly of alloy tube,the prop I used? 16x8 and it flew,Ill try and upload some piccies.regards