I have an ASP 108 with OS 7d carb. What prop should I use and how much nitro would I need? It is the older ASP. I bench ran it with 5 nitro and a beat up 16x8 MAS prop, but didn't tach it so I don't know where I am at. I was thinking of trying a 16x6 or 17x5. I would like some advice from others who have ran or know of this motor. Thanks.