7. March

Weren’t we saying Never a dull moment?

When the new ignition parts arrived, I was really eager to crank it up, then get to the brake work.

I put on the new plug wires, distributor cap and rotor, distributor condenser, and ignition coil,  then primed the carb fuel bowl and pushed the starter button.  Starter cranked strong – but engine didn’t fire.

Check connections – nothing loose.  The old rule is Fuel+Air+Spark = power.

Something’s missing.

Cranked engine with hand over carb throats – good suction (air).

Sampled fuel – looks good.  But just in case, I drained the carb, added fresh premium gas I’d just bought an hour before.  No change.

Spark test shows there’s a spark at the plugs, but I can’t tell if it’s “strong”.

Load test on battery – tester says OK (but didn’t say GOOD).  Put my portable jump start pack in parallel with the battery.  No change – cranks but engine still doesn’t fire.

Over the last four months I’ve rebuilt the carb, set valves, set timing, replaced most of the ignition system.  And probably close to a dozen other things I can’t remember.

All I can think of is the cold wet weather (we’re on our fourth blizzard of the winter today) has weakened the three year old battery, despite its being on a battery maintainer 24/7.  “Open Circuit Voltage” check does show unusually high discharge after cranking – and the starter actually slows down after only ten seconds, even when first cranked with a full charge.

Maybe a new battery should be next.  I feel the frustration factor growing.

Update Monday, March 11.  Success!

The ground wire from block to distributor was on the wrong terminal.   Move the wire, pushed starter button – engine fired immediately.  Obviously some evil spirit had moved that ground wire on a dark and stormy night.

On to the next problem:  once the engine fired, it raced at about 3000 rpm. As the engine warmed I gradually reduced choke.  Didn’t change engine speed at all.  Shut off choke and engine died.  Only way to keep engine running without choke is to keep pumping the gas.

March 14.  A clue:  one thing to look for when you can’t control engine speed, is a vacuum leak.  Couldn’t find any loose hoses or fittings.  But I did discover that I can see light coming through the joint between carb body and carb base.  There’s an “insulating flange” in that joint – but there shouldn’t be any gap.  A gap would be a source of vacuum leak.  Even with throttles closed (idle), engine manifold vacuum could pull air right through that flange gap.  Full choke would allow sufficient fuel to race the engine with all that incoming air; no choke would mean the engine has way too much air for the small amount of fuel coming through the idle jet.  Upon inspection, I found the joint itself to be slightly curved – maybe from over tightening in the past.  There was no way the flange could actually make an air tight seal.

I removed the old flange, lapped the exposed carb surfaces, then put in a new insulating flange, lightly coated with a Permatex sealing compound.  Screwed the base and body back together, and let the sealant set overnight.  No light can be seen at that joint.

March 15 – VICTORY!   I installed the refurbished carburetor and air cleaner.  Full choke, cranked, fired immediately.  Engine warmed, I gradually removed choke, engine idles smoothly.

As a friend said, Hallelujah!

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