RE: What do you think about the Magnum 4 strokes?
I love my 0.91 Magnum 4 stroke. Mounted inverted in a Senior Telemaster. I use on-board glow power (I leave it on all the time), and it will idle at about 1800-2000 rpm with no problem. It started new on the 3rd flip and has run fine ever since. On this particular one, I am only on the 2nd gallon, but I broke it in rich in the air and it has been a dream. Got it from Tower for $159 using one of their (many) email discount codes.
Funny enough, I bought a 0.91 Saito and haven't even been able to start it yet. It appears to not want to draw fuel for a prime for some reason. I have not run in to this in the past with Saito's, and have had very good luck with them in the past.
I would also like to try a YS in the future.