I had/have a cleveland models p-61 two line who could afford r/c type engines and the 3 wire system when you only earned 2.00 for cutting a neigbors yard.had k&b.23 inboard and k&b .19 ,both tprpedoe's ,outboard and did use like a 1 oz larger tank inboard.i guess i was lucky,never had the outboard quit first.wish i had a cammera back then and took pictures.oh well.would fly a few minutes on the 23 with reduced line pull ,after about 5 minutes with both running i remember arm getting tired from the pull seemed to pull more than my winder ,flite streak and ringmaster.