I just got my engine back from rebuild weisco bottom end and .40 over top end. Every thing is stock on bike w exeption of fmf slip on exhaust. I was running the oil injection I blocked that off . I used the plate and blocked.carb off. I mixed 20:1 using klotz. Plan on running 32:1 after break in. I noticed a slight knock coming from top end . I also noticed an exhaust leak from manifold. Would that cause the knock ? Also I can not get to idle right it was jetted for that exhaust before rebuild.Any suggestions I live in ny and wanna get some ridding time in before winter.Also where would you get a new spring for fmf exhaust