had a tapping/spitting noise coming from the manfold on start up, removed the heat shield to get to the manifold, started it up and the noise was coming from the 1st cylinder side, was dreading a cracked manifold but couldnt see any signs of one. So i tried to tighten up the bolts, they wasnt lose but wasnt tight ether, give them all a quarter - half turn started it up and no noise........ 😃