I've read all the various comments about the Saito and YS , "91 to 180" but what I haven't found is someone that has a OS 91 4 stroke in the ucd. How does it fly with the OS. The video that GP has and the instructions indicate the 91 should do well but that certainly isn't the impression I get from reading the various threads. I have a almost new OS and my intention is to use it but if the results are going to be terrible I might want to re-think this. Comments?