Where can I find centrifugal advance springs?

Where can I find centrifugal advance springs? This is for a 91 Ford 5.8 L with a Prestolite ignition. I'm not getting much centrifugal advance. I start at 10 Deg BTDC at Idle and it is supposed to start advancing at 1000 rpm and have a total advance of 30 deg at 4600 rpm. I'm not getting near that. I did clean around the weights and springs and they seem to move fine when I push on them.

The springs may be too stiff. There are 2 different springs and one is stiffer than the other. I'm not sure that they are correct. If I can find then springs are not expensive.

So, who knows where I can fine new springs? The part number is 3853511.

I would strongly suggest that you DO NOT change flyweight governing springs without a good means of checking how the springs have altered the curve.

Suggestion:
Find a shop who owns/operates a Sun, Allen or King distributor machine. They should have an array of springs, and will be able to accurately test the advance and make any changes as required.
They will need to see a copy of your OEM Marine ignition advance curve graph.

Thanks Ricardo. I would only be installing the stock springs but I get your concern. If this drastically changes the advance curve and I get detonation, that could really damage the engine. I have a timing light and I marked the 10, 20 and 30 deg advance positions on the flywheel. If I accelerate slowly I should be able to verify that I'm getting the advance that matches the OMC manual.

BTW It seems I found a set of stock springs.

Update. I found another owner with the same distributor and he has the same springs. One is made with thicker wire than the other so since mine are the same, they are probably stock.

I don't know why I'm not getting the full advance at higher rpm. It could have been crud interfering but it was not obvious.

Question: Can I remove the plastic piece to get at the weights better?

This may be a long shot here....... but take a look at the flyweight pins (yellow arrows) that glide within the plastic component.
These pins advance this component as centrifugal force operates the flyweights.

The slots in the plastic component control the Full In limit.

The pin at the left appears to lack complete retraction (shown by the remaining area via the green lines and arrow).
The pin at the right side appears to be completely retracted (shown by the orange arrow).

If I'm seeing this correctly, and if you were to set BASE advance while in this position, the centrifugal advance may be limited.

Keep in mind that every 1 degree of movement at this component equals 2 degrees crankshaft angle.
(Ignition advance refers to crankshaft angle)

In other words, if this part is not returning to BASE angle (by let's say 3 degrees), that equals 6 degrees at the crankshaft, or 6 degrees of advance that the system is NOT giving you.
But again..... a long shot!




Remove the felt (blue arrow) and see if there is a small C clip or snap ring that will allow you to remove the reluctor and plastic component.




By the way, you have a VR system (variable reluctor).
DO NOT bridge the gap between the reluctor and the sensor with anything metallic or conductive.
Also do not do anything that could disturb the magnetic field within the reluctor.

Hopefully you will find something that is preventing the one flyweight from fully returning to BASE mode.





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Ricardo, Thank you for the detailed information. Tell me more about a variable reluctor. One of the manuals did instruct me to use a screwdriver to cause the system to spark and I did. I did that test before I decided to replace the distributor. The good news is that the motor seemed to run fine after replacing the cap. You said not to disturb the magnetic field. What could do that? The screwdriver I used to remove the screws was magnetized. That helped not to drop the screws and washers but could it have affected the magnetic field?

You make a good point about the advance not retracting all the way. I'll look under that felt for a clip and remove the reluctor see if something is interfering. What is that felt for? I did find new springs for $25 but I may not need them.