1971 Ford F-100 wont start

Points or electronic ignition. If points replace point and condenser set dwell at 30 degrees while cranking. Then check for cracked coil tower or bad rotor/dist cap.

ARE YOU REMOVING AND PLUGGING OFF THE VACUUM ADVANCE HOSE TO THE DISTRIBUTOR WHILE YOU ARE "TIMING". THEN REPLACING IT AFTERWARDS?

BEING A '71. THINGS GET OLD AND FAIL

IF YOUR HARMONIC BALANCER HAS "SLIPPED" (THE 2 PIECES ON EITHER SIDE OF THE RUBBER). THEN YOUR TIMING MARK(S) ON THE HARMONIC BALANCER IS NOW USELESS.
IF THIS HAS HAPPENED AND THE "SLIP" WAS EXTENSIVE, YOU MIGHT BE ABLE TO COMPARE A NEW BALANCER'S CRANKSHAFT'S KEY-WAY'S POSITION TO THE TIMING MARK(S) WITH YOURS

"MY" KEY-WAY" IS STRAIGHT UP WHEN I INSTALLED MY NEW "CLOYES TRUE DOUBLE ROLLER TIMING CHAIN". MY RULER IS LINED UP OVER THE ALIGNMENT MARKS ON THE 2 GEARS. WHEN I INSTALL THE BALANCER THE "TIMING MARK" ON IT WILL CORRESPOND WITH "0" ON MY SCALE

I'M NOT TELLING YOU TO TAKE IT APART DOWN TO THE TIMING CHAIN.I JUST WANT YOU TO UNDERSTAND HOW A "SLIPPED" HARMONIC BALANCER WILL "UNKNOWINGLY" MOVE THE TIMING MARK FROM BEING "IN SYNC" WITH THE "REAL TIMING".

MAYBE MY PICS WILL AID IN UNDERSTANDING

THE MEDIC

CJ becaue balancers in that era were two piece there was a rubber ringbetween the two pieces and it would break and let the outer ring which has the timing mark on it slip thus letting the timing off. As far as ananswer to this question one thing I forgot ot mention is check compression because if all the cylinders have low compression the chain has probably jumped one or two teeth.

WELL I RECKON I'M NOT GETTING EMAIL NOTIFICATIONS NOW.2ND ONE I'VE STUMBLED ON

THE SLIPPING OF THE HARMONIC BALANCER DOES NOT CHANGE THE TIMING OR MAKE IT WRONG!

. WHEN."YOU". ATTEMPT TO "TIME IT". AFTER IT HAS HAPPENED (EVEN IF IT HAPPENED/ SLIPPED MONTHS BEFORE)."YOU" (UNKNOWINGLY). SET THE TIMING WRONG, BECAUSE THE "POINTER/ SCALE" IS NO LONGER "IN SYNC" WITH THE POSITION OF THE CRANK
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THE HARMONIC BALANCER THING DOES HAPPEN, BUT IT'S NOT REAL FREQUENT. BELOW IS MORE FREQUENT, I CAN SHOW YOU THE CORRECT PROCEDURE IF YOU DESIRE, USING PICS I MADE WHEN TIMING MY '77 JEEP
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DID YOU UNDERSTAND THE "PLUG THE VACUUM LINE TO THE DISTRIBUTOR OFF". DURING THE TIMING PROCESS. WITHOUT DOING THIS. YOU MAY BE 10 DEGREES OR MORE "OFF" ON TRUE TIMING. THIS MIGHT BE YOU ONLY PROBLEM (WE HOPE) 5 MINUTES OF RE-TIMING MAY BE YOUR FIX

IF NOT, KEEP US POSTED ON WHAT YOU ARE STILL UP AGAINST

WE LIKE UPDATES.I'LL BOOKMARK THIS ONE SO I CAN SEE YOUR PROGRESS

THE MEDIC