Steve thanks very much for all the info. I was lead to buy a 91 since the engine has the same phisical dimensions of a 61 (at least in the OS case) I was looking also for a 4 stroke and since NOW I know that the Saito 100 is too big I will look into a 82. In planes as the Skybolt, where you need a heavy engine to balance your plane, I would rather have a bigger engine than plain lead. As for the ground clearence, I can always use a 3 bladed prop, that would look even better on that plane. I will see what to do. As for the super tigre I wasn't aware that now they are built in china, but what isn't nowdays. Everything is biult there.....

Thanks for all the tips I think I got myself a good picture of what I have to do.....