how can i tell if timing belt is broken on a miata?

Answer 1

A timing belt should be changed at the time your manufacturer tells you to change it. This is at about 100,000 KMS. If you ignore this there is a real possibility of the belt breaking and causing total engine failure.
Its right that if the engine wont run now and you check the operation of the cam shaft and its not rotating the belt may be broken. Feel free t osk me more.

Answer 2

Even if it is not broken, it may have stretched.
General symptoms of timing belt problems are a drop in MPG, and poor performance.
There is a maintenance problem on the key ways, and if the key was not put back in right, the crank could of been damaged. Repairs are not cheap when this happens and the symptoms are similar.
Before jumping to the conclusion that it is the timing belt, replace the fuel filter, plug wires and spark plugs.

Answer 3

Your car won't run if the timing belt is broken, a broken timing belt can do some $erious damage, you should have it replaced every 50,000 - 75,000kms otherwise you are risking the expense of new pistons and a full top end rebuild.

Answer 4

If the engine is running, then it is not broke. If it is not running, you could remove the valve covers and see if the valves are moving when the engine turns over.