number 1 cylinder is not firing correctly. It does have good 50 # compression. By laying spark plugs on top of block with wires attached the plug does fire when brought to top dead center on a compression stroke. With timing set with the gage set at 2 1/2 in. and spark lever fully retarded engine starts very well. No 1 cylinder will not fire. We are using modern plugs. They are autolite 56's. Could plug be too cold?
What gap are you running? maybe try a little (.002"-.005") wider or narrower gap.
Have you tried swapping plugs around?
What gap does Bitner recomend?
The Tru-Fire fires two plugs at one time (kind of a wasted spark ignition system). That being the case, if the other three plugs are firing fine, I would look for an issue in the coil box. It could be that the contact fingers in the box have turned slightly and are not making contact, a carbon track that is shorting out #1 in the coil box wood (plastic rebuild kit for the coil box fixes this) or if the contact fingers are repro replacements they might not maintain their springiness and loose contact. Make sure that the Tru-Fire has a good ground at the timer. (loosing the ground is a quick way to kill the unit).
Evan in Paso
In re-reading your post I see that you mentioned that when the spark is set at full retard, "engine starts very well. No 1 cylinder will not fire." Check to see if the timer control rod is hitting one of the contacts on the timer cover. The Tru-Fire timing "brush" is manufactured with some advance built-in.
Evan in Paso
Al : change your # 1 spark plug ! # 1 plug is always a problem with Model T's
Al, your #1 and #4 spark plugs are daisy chained together through the head. They divide the spark that is applied.
That means the gap on #4 is much larger and hogging the spark or #1 is fouled, which often happens, if you do not have the stove pipe on your carburetor.
The best test to isolate the problem is to exchange #1 and #2 spark plugs and also exchange #3 and #4 spark plugs. Then see if #1 gets a good spark again.
The problem could be in the coil box or spark plug wire, if the problem remains.