Our timing belt kit is a little more expensive because it includes the tensioner and idler pulleys. We find that almost every Miata needs new ones when doing a timing belt. It also includes the timing belt (made by Continental), cam seals, front crank seal, a valve cover gasket, thermostat neck O-ring and a CAS O-ring. Accessory belts sold separately. Don't get caught on a Saturday afternoon without parts you need!
This kit does not include a new tensioner spring, as it doesn’t need to be replaced. The tensioner spring doesn’t move back and forth during normal operation, it just pulls the tensioner pulley into the correct position during installation – it could actually be removed once the tensioner bolt has been tightened. Therefore, the spring isn’t fatigued and doesn’t need to be replaced.
This kit is for the NA8 engines.
We also have a full tool kit to help make this easier for you.