ORIGINAL: 4-Stroke
I hav a 100 saito that is going on it eventually but I am in the beginners forum for a reason. Some some lazy circles and a good aproach and soft landing would be great fun for me. The issue is weight. The 100 saito and 70 magnum are almost identical in weight.
Put it on it now. That's why we have a throttle. Lazy circles can be done with the 100, too. You are better off with the more powerful engine if you have to add lead.