I have went through just about all the threads involving the Shoestring about which engine to use and I am still lost, seems like alot of them will require you to add weight to the tail to get it to balance right. I had a Magnum 91 four stroke on mine and I wasnt that impressed with the speed, I had a 14x6 prop on it. Anyways which engine out there is going to give me the most power and not going to require alot of added weight in the tail. I was looking at that Saito 82 but not how much power I will get out of it.