Rough Running

[den912]

Took my car out today and it ran real bad,when going up hill's there was no power and made a real rattle noise, the exhaust sounded like it was blowing when you accelerate,it.s a 1.7 on twin carbs ,it ran fine yesterday,any ideas what could be happening

[Dave at Pelican Parts]

Check your ignition timing. Also check for vacuum leaks. If the rattle is pre-ignition, it could be very bad for your engine in the long term. Pre-ignition could be caused by the timing being overly advanced, or the fuel mixture being very lean, or other less-likely causes.

Check the valve lash. A rattle could be loose valve gaps.

--DD