My dad has a new 2004 Fastrak with a Briggs and Stratton 17.5 hp engine with about 10 hrs on it. We are going to change the oil but have no manual for the engine. Is the recommended weight 10w30? Is it ok to use synthetic on a new engine or should we run it a few hours on regular oil first? Kohler doesn't recommend synthetic for the first 50 hrs and I didn't know if Briggs had the same recommendation. Thanks.