Just got back from the field, I will weigh it and send you the info. I used a 15x10 with my 160 and also with the saito 150. The 18x8 may be too much prop to get much out of that engine. Maybe others have had luck with that but I think that is too much for that airframe and engine combo. I use an 18x8 or 10 with my 40-50 cc gas engines.