Have new sealed 1250 15 races on it. Can hear a chirping sound when you crank it over cold. Checked exhaust gaskets, head gasket, compression, did a leak down and all are fine. Sounds almost like a compression release and is definitely on an exhaust stroke. Don' t hear it when motor is hot or running. Checked for air leaks by the carbs, and all around where the head joins, re-torqued the head and found nothing. Motor runs strong, idles fine, just have this puzzling chirp sound. Anyone ever had something like this?