RE: Engine 4 Piper cub
The Magnum 4 strokers are supposed to be good. But I have 7 Saito's. I like the Saito over any other 4 stroker I have seen or handled. Not knocking Magnum's but Saito only makes 4 strokes. I feel for the extra money I would still choose Saito. If money is tight and cost is a factor go for the Magnum. Either one will work well. I feel the longevity of the Saito will balence out the cost difference. I hope this helps. Also check weights I believe the Saito's are the lightest 4 strokers out there. I could be wrong so check numbers. It may be that your plane may need a lighter or heavyer engine. Buying the right one could help balance the plane.
Mark Shuman