Distributor Advance / Retard slot

[jgbrown59]

In the process of doing some restorative work on my 59FL (owned since 1980) I found the slot in the distributor shaft housing that controls the distributor advance / retard travel to be considerably worn on the advance stop side.
59 distributor slot wear.jpg

I have the shaft housing from a 47EL (approx. 0.750” wide) and 48FL (0.870” wide) shown below. All of them have different widths.
48 dist advance gap.jpg

Over the past few years I’ve had suspicions my 59 distributor was traveling too far when retarded, potentially impacting starting (to much retard). I realize I can control the distributor travel with the cable adjustment but I’m just anal enough to want the distributor to hit its stops so I want the correct opening.

Does anyone know what the factory width of the slot is? I’ve welded the worn slot for the 59 (now 0.685”) shown below, but need to clean it up and would like to get it back to the original, or maybe slightly narrower, width.
59 dist gap.jpg

Palmer answered my question - Page 643, 3rd Revised Edition says 13/16” (0.8125”). I should have looked there first!


Since I wrote this up, then found the answer, any contributing opinions or commentary?


Thanks,


Jim

[T. Cotten]

Gosh, Jim,

The only thing that matters is how you time it to its fully advanced stop.

Most Folks find they start easier if they are not fully retarded anyway.

(By the way, HD never used a 'distributor', but Indian did!)

....Cotten
PS:
Somebody please identify this timer that's aimed back at the motor?
Its .935" at the top, so it can't be HD, right?

TIMER.jpg
Thanks in advance as always,

[jgbrown59]

Tom,

Yes, I understand the right side is the one that matters as the fully advanced stop. My concern is if the slot is too wide, and the cable is adjusted to move the timer stop to stop, as I assume was the motor company's intention, the timing would be retarded further than desgined, and the engine may not start as well. I have always liked the sound and positive feel of the timer hitting both the fully advanced and retard stops. I've had this bike for almost 50 years so most of the wear in the slot is from my use.

What I may really be asking is if anyone has found a sweet spot in the amount of retard that facilitates starting and minimizes kickback. Something like 60, 70, or 80% of full retard?

To address your Timer question Tom - I don't completely understand the question and most likely do not know the answer anyway.


Jim

[Lyle Manheimer]

JG,
I have owned my 1964 police FL for 15 years. I ride it quite often, It still has the original dual point timer. I last timed it maybe 5 years ago after cleaning the points with a plastone. Never checked stops or slots. I am sure I timed it with a 12 volt light, have to use an external power source as it is still 6 volt.
It almost always starts first hot kick. My drill is four kicks throttle wide choke full on. Take choke off and back on one click. Retard spark maybe 5-10% and kick. Voila, go for a ride after taking choke off and advancing timer. I have never found much need to mess with the advance unless I am riding double ascending a steep grade. Dual point timer is the original single fire ignition from HD, right Tom?

[T. Cotten]

Dual point timer is the original single fire ignition from HD, right Tom?

I really don't know, Lyle,

As I am not familiar with many early models.

If fully retarding does not kill the motor, I can't see a problem.

.....Cotten

[duffeycycles]

I never go to full retard to start my bikes, guessing, maybe 70%.

[droptopford]

As far as a 'sweet-spot' goes... for me, it's somewhere around halfway between fully advanced and fully retarded. '57 FLH will start fully retarded but it seems to fire up better around half way without (too) much kick-back.
Once you have the fully advanced stop dialed in, and the bike running and warmed up, you should be able to fully retard the spark without the engine stopping.
I use the timer advance lock stud as an index to judge where to set timing for starting.

[dukekleman]

Quote:
"Since I wrote this up, then found the answer, any contributing opinions or commentary?

Thanks Jim"

Jim,
You'll find the early manual advance, outer band strap version breakers have approximately 16 degrees of timing variation from full retard to full advance. If things are correct and not worn out. This means movement of 0.032" equals 1 Degree if you perform the math.

While the later manual advance versions have approximately 14 degrees of timing variation from full retard to full advance. If things are correct and not worn out. This means movement of 0.025" equals 1 degree if you perform the math.

Later centrifugal advancers have more degrees of timing variation from full retard to full advance.

As others have stated, be sure your full advance timing setting is correct. I have found that 1/2 to 2/3 advance is appropriate for starting. This varies if items are worn and endplay is not shimmed correctly.
Beware there are MANY items that stack up, wear and cause variation in the manual advance design.

I hope this helps,

Duke Kleman

[T. Cotten]

Quote:
"Since I wrote this up, then found the answer, any contributing opinions or commentary?

Thanks Jim"

Jim,
You'll find the early manual advance, outer band strap version breakers have approximately 16 degrees of timing variation from full retard to full advance. If things are correct and not worn out. This means movement of 0.032" equals 1 Degree if you perform the math.

While the later manual advance versions have approximately 14 degrees of timing variation from full retard to full advance. If things are correct and not worn out. This means movement of 0.025" equals 1 degree if you perform the math.

Later centrifugal advancers have more degrees of timing variation from full retard to full advance.

As others have stated, be sure your full advance timing setting is correct. I have found that 1/2 to 2/3 advance is appropriate for starting. This varies if items are worn and endplay is not shimmed correctly.
Beware there are MANY items that stack up, wear and cause variation in the manual advance design.

I hope this helps,

Duke Kleman

Thanks, Duke!

Any idea what degrees the '65-'69 auto-advance was?

(I agree with Panic, it was really an auto-retard.)

Thanks again,.. ... .. in advance.

....Cotten

[dukekleman]

Thanks, Duke!

Any idea what degrees the '65-'69 auto-advance was?

(I agree with Panic, it was really an auto-retard.)

Thanks again,.. ... .. in advance.

....Cotten

Cotten,

If components are within specifications, you'll see 28-30 degrees of variation from full retard to full advance on those auto advance units.

Hope this helps,
Duke Kleman

[T. Cotten]

Cotten,

If components are within specifications, you'll see 28-30 degrees of variation from full retard to full advance on those auto advance units.

Hope this helps,
Duke Kleman

Wow, Duke!

That's pretty much an average of the manual assemblies, implying a degree or two is allowable margin of error.

So let us rephrase Jim's question: Can it over-retard?

....Cotten

[droptopford]

Wow, Duke!

That's pretty much an average of the manual assemblies, implying a degree or two is allowable margin of error.

So let us rephrase Jim's question: Can it over-retard?

....Cotten

Maybe I'm missing something here Cotten, but didn't you mean to say that's about "double the average of the manual assemblies"? (That's the way I'm reading those numbers anyway)

I was also wondering how you could possibly over-retard the manual advance if the auto-advance units are dropping off that far and still running smoothly.?.

[dukekleman]

Wow, Duke!

That's pretty much an average of the manual assemblies, implying a degree or two is allowable margin of error.

So let us rephrase Jim's question: Can it over-retard?

....Cotten

Cotten,

The short answer is yes it can.
The reasons for a over retarded scenario are many...
The reason also vary based on what year category we are conversing over.

A statement I use often, "Everything connects to Everything" really comes into play in this conversation.

Here are a few common problematic areas that make a HUGE difference.
Some of these vary based on the year group, whether updates have been performed and/or aftermarket parts used...

A) Pinion Gear fitment to the Pinion Shaft
B) Pinion Gear to Circuit Breaker Drive Gear fitment
C) Circuit Breaker Drive Gear End Play
D) Circuit Breaker Drive Gear to Circuit Breaker Driven Gear fitment
E) Circuit Breaker Driven Gear Shaft Endplay

IMG_20250329_141820572.jpg
IMG_20250330_124441846.jpg

Those 5 items themselves are commonly found to have issues when customers come in for a quote "quick tune up".

I'm not saying you can't make them run, but just because they run doesn't mean they are running right. Without getting into details of how these affect the Fuel System Calibration, I'll just say they are crucial and overlooked on the "Rebuilt engines" I run across occasionally. Often passed off as "Runs as it should".

The reason I bring up the following items and statements is because Jim stated he is anal and he wants things right. I don't blame him, I'm the same way.
If I'm doing a job, I'll do it to the best of my abilities while finding and developing ways to do it even better sometimes.

I hope this helps,

Duke Kleman

[T. Cotten]

Maybe I'm missing something here Cotten, but didn't you mean to say that's about "double the average of the manual assemblies"? (That's the way I'm reading those numbers anyway)

I was also wondering how you could possibly over-retard the manual advance if the auto-advance units are dropping off that far and still running smoothly.?.

Thanks, DropTop!

Like I posted, wow.

....Cotten