A bill to tighten up Maine’s motorcycle helmet law is moving forward in the Legislature. The bill would require anyone under 18 who is operating or riding on a motorcycle to wear a helmet. The present law applies to those under 15. The measure won a second vote of approval without debate Thursday and still faces further House and Senate votes. A separate bill calling for a helmet law applying to all riders and operators remains in the Transportation Committee, which is scheduled to discuss it Friday.