Yes the standard timming settings should be followed if the engine is stock.
You may need to retard the timming if you have carbon build-up in the heads or poor quality fuel causing pinging (preignition).
You may need to advance the timming if your running LPG or a higher octane fuel and want to take advantage of the extra power at hand.
Genrally it stays in the stock position.
Being a points distribtor your always resetting the timming due to stretch in the timming chain and wear on the points contacts and rubbing block which alters your dwell angle.
Testing your distibutor advance mechanism;
There are 2 advance systems, vacuum and mechanical. If one is rooted you wont reach your desired total advance.
First the vacuum one.
On the side of the distributor is a round unit with a diaphram inside and a vacuum hose connected to it.
As a vacuum occurs inside your intake manifold the vacuum travels down the hose to the diaphram inside the unit on your distributor.
When the diaphram moves, it has a shaft connected to it which goes into your distributor and turns the contact plate to advance the timming.
To test the vacuum advance.
Remove your distributor cap and check that the shaft from the vacuum advance is connected to the plate the points sit on.(i have found them unhooked afew times).
Take a hose running from the distrubutors advance unit, put it in your mouth and suck on it.
You should see the plate with the points rotate.
Releasing the vacuum (stop sucking on the hose) should let the plate spring back to its start position.
This proves the mechanism works.
Now suck on the hose and while sucking it put your tounge over the hose to hold the vacuum.
The plate should move as usual and stay in its moved position without going back to its no vacuum position.
This proves there are no pin holes or slow leaks in the diaphram.
Another quick shortcut to testing the vacuum advance is to run the engine with a timming light at idle and suck on the hose while observing the timming mark advance while sucking and return to base when not.
Mechanical advance;
Under the points plate are 2 weights held with springs, as the assembly spins faster, as engine revs are increased, the weights move because of centrifugal forces and drive a cam that turns your rotor button forward to advance the timming.
To test the mechanical advance.
Remove the distributor cap.
With the rotor button still fitted you should be able to turn it (the rotor button)5 to 10 degrees in only one direction and it should spring back.
They are known to seize up in older cars and may need to be dissassembled and lubricated.
I have seen them bind up many times, just disassemble, clean and lubricate it so its free again.
Another quick way to check your mechanical advance is to disconnect your vacuum advance hose and start the engine with a timming light connected.
When you rev it hard (higher rpm) the timming should advance.
So either vacuum or mechanical advance, advances your timming, each a little but it takes both to reach total maximum advance.
Hope this helps you a little.
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