Triumph Repair: Engine doesnt shut off, combustion chamber, preignition

Question
Howard,
After driving my tr6 and reach my destination, I turn off the key, car still continues to run for about 30 seconds. Is the timing off? Or, could it be the carbs are not tuned properly? Thank You in advance

Answer
Hi Carlos,
If it was running and making noises and not running smoothly, it was Detonation/Preignition. If it was running smoothly and you could rev the engine with the throttle then it was something else.

If it was detonation/Preignition then it was either overheating, carbs too lean, ignition too far advanced or regular gas instead of premium gas. It can also be caused by the wrong heat range spark plug or even excess carbon in the combustion chamber.

If the engine would run smoothly and you could rev the engine up after you turned off the key, then you may have a wiring problem that keeps the charging system active and powering the ignition.

Howard