Breaker Point Tune Up...
TeamRush
Active Jeeper
Some of you still run breaker points.
That's your choice, since it's very easy and inexpensive to switch to electronic 'Breaker-less' ignitions.
This is for the guys running breaker points that might or might not know EXACTLY how to tune them up...
First,
Grab the rotor/shaft and give it a shake back and forth.
Do this about six indexes (like cutting a pie).
If you can see/feel the shaft MOVE SIDEWAYS,
There is too much slop in the upper bushing/shaft contact point for the breaker points to work correctly.
Those of us old enough to remember when breaker points were the ONLY way to do things,
Will remember there are a few things breaker points need, and MUST have to survive and work correctly.
One of those is top bushing ('Bearing') lubrication.
Jeep used Delco Remy distributors many times,
And Delco Remy distributors often have a grease zerk (for grease gun) or Oiling Hole in the distributor housing under the main head.
Later owners might not know it's there and don't lubricate.
Later Delco Remy (Aluminum Housing) has a GREASE WELL in the bottom of the distributor head.
This grease gets old and dries out, needs to be changed fairly regularly,
And this requires removal, disassembly of the distributor to reach/clean/lube.
One of the things we used to do was mill out that grease well, install a sealed roller bearing to keep wear/shaft wobble to a minimum.
It's a lot of work...
---------
Once you know the shaft isn't sloping around, and you aren't wasting your time/effort/money,
Then move to the LOBES on the advance head.
These 'Cam' Lobes are what lifts the breaker point arm, opening/closing the breaker points.
THIS SURFACE MUST BE LUBRICATED EVERY TIME YOU SERVICE THE BREAKER POINTS!
This *Should* be every 500 to 1,000 miles.
Again, these get friction wear which lack of lubrication speeds up that wear process, and will become out of specification over time.
Like any 'Cam' Lobe bump,
There is an Approach Ramp,
Maximum Lift (Top Out),
And Departure Ramp.
Where these Lobes wear most times is the top, Maximum Lift.
When this surface wears, the breaker points have to be adjusted to allow the 'Gap' in between the breaker point faces...
When the 'Bump' wears too much, the Ramps and Maximum lift 'Bump' don't get the breaker point faces open FAR enough, and the breaker points don't stay open long enough,
OR,
They keep the breaker points open TOO LONG.
There is ONLY ONE WAY to check this particular kind of wear,
And that is with the Dwell Meter you need to set the breaker point opening with anyway...
---------------
So, once you have no significant shaft/bushing wear,
And you have the 'Cam' lobes lubricated on the distributor shaft,
Then you move to initial gapping of the breaker points,
Which anyone with breaker points probably knows how to do this...
The first step in Gapping IS NOT getting out the feeler gauges!
The first step is getting out the breaker point file!
Without flat, square, true faces, there is no way to accurately gauge or tune breaker points.
Once you file them square, rotate the engine over where the lobe on the shaft has the breaker points at FULLY OPEN position,
Check gap with a BREAKER POINT GAUGE,
That is NOT a flat feeler gauge,
But a ROUND WIRE gauge.
This will set you ready for start up, Dwell and Timing.
---------
Dwell is the amount of time, expressed in degrees,
The breaker points are open/closed.
Without a Dwell Meter, you simply can not PROPERLY get the breaker points timed/tuned.
With most breaker point sets, you will find an 'Allen' screw that fine tunes the gap setting,
Use a Dwell meter to SEE what the breaker points are doing, then make corrections at that Allen screw.
Dwell WILL effect timing,
Timing WILL NOT effect Dwell.
Once Dwell is set,
Remove the line to the distributor vacuum advance canister and plug the line,
Then set your timing with a timing light.
Don't forget to hook the vacuum advance line back up!
------
Once you have Dwell & Timing set,
Then rev the engine a few times with the Dwell meter still attached.
*IF* the Dwell moves around, up and down with RPM,
Or it moves around at all,
Then you have an issue you need to correct.
DWELL SHOULD NOT MOVE WITHOUT A MANUAL ADJUSTMENT TO THE BREAKER POINTS.
--A 'Wondering' Dwell reading is a sure sign the top busing is worn out,
--A Dwell adjustment that won't get you into the proper Dwell reading range means the 'Lobes' are gone off the distributor shaft cam.
That's your choice, since it's very easy and inexpensive to switch to electronic 'Breaker-less' ignitions.
This is for the guys running breaker points that might or might not know EXACTLY how to tune them up...
First,
Grab the rotor/shaft and give it a shake back and forth.
Do this about six indexes (like cutting a pie).
If you can see/feel the shaft MOVE SIDEWAYS,
There is too much slop in the upper bushing/shaft contact point for the breaker points to work correctly.
Those of us old enough to remember when breaker points were the ONLY way to do things,
Will remember there are a few things breaker points need, and MUST have to survive and work correctly.
One of those is top bushing ('Bearing') lubrication.
Jeep used Delco Remy distributors many times,
And Delco Remy distributors often have a grease zerk (for grease gun) or Oiling Hole in the distributor housing under the main head.
Later owners might not know it's there and don't lubricate.
Later Delco Remy (Aluminum Housing) has a GREASE WELL in the bottom of the distributor head.
This grease gets old and dries out, needs to be changed fairly regularly,
And this requires removal, disassembly of the distributor to reach/clean/lube.
One of the things we used to do was mill out that grease well, install a sealed roller bearing to keep wear/shaft wobble to a minimum.
It's a lot of work...
---------
Once you know the shaft isn't sloping around, and you aren't wasting your time/effort/money,
Then move to the LOBES on the advance head.
These 'Cam' Lobes are what lifts the breaker point arm, opening/closing the breaker points.
THIS SURFACE MUST BE LUBRICATED EVERY TIME YOU SERVICE THE BREAKER POINTS!
This *Should* be every 500 to 1,000 miles.
Again, these get friction wear which lack of lubrication speeds up that wear process, and will become out of specification over time.
Like any 'Cam' Lobe bump,
There is an Approach Ramp,
Maximum Lift (Top Out),
And Departure Ramp.
Where these Lobes wear most times is the top, Maximum Lift.
When this surface wears, the breaker points have to be adjusted to allow the 'Gap' in between the breaker point faces...
When the 'Bump' wears too much, the Ramps and Maximum lift 'Bump' don't get the breaker point faces open FAR enough, and the breaker points don't stay open long enough,
OR,
They keep the breaker points open TOO LONG.
There is ONLY ONE WAY to check this particular kind of wear,
And that is with the Dwell Meter you need to set the breaker point opening with anyway...
---------------
So, once you have no significant shaft/bushing wear,
And you have the 'Cam' lobes lubricated on the distributor shaft,
Then you move to initial gapping of the breaker points,
Which anyone with breaker points probably knows how to do this...
The first step in Gapping IS NOT getting out the feeler gauges!
The first step is getting out the breaker point file!
Without flat, square, true faces, there is no way to accurately gauge or tune breaker points.
Once you file them square, rotate the engine over where the lobe on the shaft has the breaker points at FULLY OPEN position,
Check gap with a BREAKER POINT GAUGE,
That is NOT a flat feeler gauge,
But a ROUND WIRE gauge.
This will set you ready for start up, Dwell and Timing.
---------
Dwell is the amount of time, expressed in degrees,
The breaker points are open/closed.
Without a Dwell Meter, you simply can not PROPERLY get the breaker points timed/tuned.
With most breaker point sets, you will find an 'Allen' screw that fine tunes the gap setting,
Use a Dwell meter to SEE what the breaker points are doing, then make corrections at that Allen screw.
Dwell WILL effect timing,
Timing WILL NOT effect Dwell.
Once Dwell is set,
Remove the line to the distributor vacuum advance canister and plug the line,
Then set your timing with a timing light.
Don't forget to hook the vacuum advance line back up!
------
Once you have Dwell & Timing set,
Then rev the engine a few times with the Dwell meter still attached.
*IF* the Dwell moves around, up and down with RPM,
Or it moves around at all,
Then you have an issue you need to correct.
DWELL SHOULD NOT MOVE WITHOUT A MANUAL ADJUSTMENT TO THE BREAKER POINTS.
--A 'Wondering' Dwell reading is a sure sign the top busing is worn out,
--A Dwell adjustment that won't get you into the proper Dwell reading range means the 'Lobes' are gone off the distributor shaft cam.