ORIGINAL: BobMaine
ORIGINAL: bingo field
You can't go wrong with the Saito's. I would opt for the smaller one, the 91, as you just don't need the 100 on that size plane. I can hang my Venture 60 on the prop with the 91, it has that much power with a 14x6 MAS. The 100 you would never get over 3/4 throttle, unless you were testing the glue joints. Have fun with that, you should love it.
You CAN go wrong with Saitos, every once in awhile someone (me) gets one that shakes like hell and you will pull your hair out trying to get it to smooth out. My Saito 1.00 shakes so bad it is destroying the electronics and the plane its self. Have not found a way to fix the shaking yet. Beware.
I was reading the overview on Horizon Hobby for the Saito 1.00. I read something that reminded me about what you said about your engine shaking so badly. But here's what the overview said, not sure if you tried any of this:
The Saito 100 idled and transitioned beautifully from the first start due to the included new Hangar 9™ Super Plug (HAN3011) that now comes with all Saito engines. This plug greatly improves idle and transition in all four-stroke engines.
And it also said this:
Our staff commonly uses 30% heli fuel in Saito engines, as it not only gives better top-end performance but it runs smoother, gives a better transition, and runs cooler.
So maybe you're not running a high enough nitro %.