Hi guys looking for a little info on prop distance from cowl, 50cc sukohi SU-26 .

Looking at the picture the Prop is almost 1" on the top side of the cowl and maybe 3/4" at the bottom ( the difference it the built in thrust ). Does this seem an adequate amount of clearance? right now the stock muffler on my DL-50 is really close to the cowl ( Probably will have to wrap the can in header wrap ) so I don't want to move the engine forward any more if I don't have to or I will need to cut the cowl to clear the muffler.