Topic: timing...problem setting points. (SOLVED)

[KeithB]

1972 CB750 K
I have read the posts about aftermarket points and plates and checked that I have the TEC style.
Actually tried 3 different TEC plates and all the methods to get timing right.
It is practically impossible to get the timing on the mark using both the static and strobe method.
I have cut the slots as far as possible and juuuuust got each side to be fairly close but still needs more retard.
It is beyond reasonable that this heavy a mod is required! Didn't have this problem with my '78 CB750.
I does start and run but as I am trying to work out carb adjustments, I would like to have the timing correctly set.
As the advance plate has the timing markers, is it possible I have the wrong spark advance plate?
The one I have is marked ADI25-01.
I'm going to install a Dyna S DS1-2 but may still have the same issue trying to get it timed correctly.
Any ideas welcome as I don't have much hair left to pull out

http://imageshack.us/photo/my-images/600/advanceplate.jpg/

[LesterPiglet]

Search is broken at the minute, use the google search on the left.
Open a photobucket account and link pics from there. www.photobucket.com

[luap]

not familiar with the 750, for the 550 are you trying to get the hash mark to line up in the same place when you do static an strobe, stactic should line up tdc an strobe should line up at the pre tdc hash marks,

[KeithB]

Can't get either method to line up as you suggested.
The manual lays both methods out quite clearly.

[TwoTired]

Check out the ignition FAQ about setting points and shimming the plate.

[KeithB]

I did read about setting the points by Honda Man. "working with those cheap ..."
Will look again.
Thanks Mate!

[TwoTired]

Maybe this will help..
http://forums.sohc4.net/index.php?topic=5752.msg47539#msg47539

[lucky]

1972 CB750 K
I have read the posts about aftermarket points and plates and checked that I have the TEC style.
Actually tried 3 different TEC plates and all the methods to get timing right.
It is practically impossible to get the timing on the mark using both the static and strobe method.
I have cut the slots as far as possible and juuuuust got each side to be fairly close but still needs more retard.
It is beyond reasonable that this heavy a mod is required! Didn't have this problem with my '78 CB750.
I does start and run but as I am trying to work out carb adjustments, I would like to have the timing correctly set.
As the advance plate has the timing markers, is it possible I have the wrong spark advance plate?
The one I have is marked ADI25-01.
I'm going to install a Dyna S DS1-2 but may still have the same issue trying to get it timed correctly.
Any ideas welcome as I don't have much hair left to pull out

http://imageshack.us/photo/my-images/600/advanceplate.jpg/

ARE they NEW points??

Do you have a dwell meter?
If not you can get one at sears. Got to have it .
The dwell is a function of the points gap. They are related.
Do NOT use a timing light to set the points, because just the impedence will alter the results.
Instead use a Volt/ohm meter, set on the ohms x 1000 scale Key off of course.

[KeithB]

I understand about the rotation of the plate and cut longer slots to allow more counter clockwise rotation and more retard.

I read and re-read your post and still can't quite get it.
Could you clarify your mod a bit more? Questions in caps.


If you remove the points from the plates and loosen all three large plate mounting screws, you will find that that large plate will move some distance radially on the mount posts machined into the engine case. THIS IS A SNUG FIT ON MY BIKE.
  This movement is why you run out of adjustment range, as some plates are different diameters, and some engines have been machined to a different tollerance limit.  The spring pressures of the points pushes the plate in the opposite direction against the mount post. This puts both points in a position relative to where adjustment range is limited.
What to do.  While you have the points removed from the plate (thus all spring tension) and all three mount screws lossened, find the largest feeler gauge that will insert in the gap between mount post and large breaker plate.  YOU MEAN OUTSIDE EDGE OF PLATE AND ENGINE CASING AT 4 OCLOCK? EFFECTIVELY PUSHING PLATE TOWARD 10 OCLOCK
 This is also the point gap error and directly impacts timing.  Reinstall the 1-4 points, set the gap CONFIRMING GAP IS SET WHEN CRANK IS 90 DEG FROM F1-4 MARKER
 and the 1-4 static time CONFIRMING BREAKER POINT OPENS AT F1-4 MARKER
with the feeler gauge still inserted in the lower right mount post to breaker plate gap.  I sacrificed a feeler blade and cut one in an L shape to fit under the mount screw washer, so it wouldn't fall out during plate rotation. This way I can change the 1-4 timing while the bike is running (dynamic timing) or not (static timing).  In my experience, this brought the adjustment slot for both 1-4 and 2-3 points into an acceptable adjustment range.

[KeithB]

Lucky,
Yes, new points.
Using the light bulb method as indicated in Clymer manual. Confirming with strobe, again as indicated in manual.

I would like to verify what each set of marks is for. It's not like these manuals are always correct.
From the pic in my OP there are 3 sets of marks at the top.
From the left is "TI" then "FI1.4" then "II"
What do you understand as the use for each one?

[Spanner 1]

Keith.... setting your timing is a 2 step process. First thing is to set your point gaps. I have not seen any reference in this thread as to how you have set the gaps ?? Wrongly set point gaps = timing plate turned all the way against the stops. Please explain how you set the point gaps 

[KeithB]

From Clymer manual...condensed
Rotate crankshaft until points for 1-4  fully open.
Set gap to .012 - .016 "
Do the same for points for 2-3
The problem here is that they don't indicate a starting place for the plate.
The picture shows the plate at roughly mid way on the adjustment posts.
This is probably the start of the problem...
Also, the cam seems to be able to go into the advance arms both ways.
That is to say that there is no keyway for "one way" installation.

[TwoTired]

If you remove the points from the plates and loosen all three large plate mounting screws, you will find that that large plate will move some distance radially on the mount posts machined into the engine case. THIS IS A SNUG FIT ON MY BIKE.

The springs on the points make it seem to be a snug fit, but it hardly ever is.  Either remove the points from the plate and check, or block the point open so the rubbing block can't touch the point cam.  Loosen the plate and see if it will move laterally.

YOU MEAN OUTSIDE EDGE OF PLATE AND ENGINE CASING AT 4 OCLOCK? EFFECTIVELY PUSHING PLATE TOWARD 10 OCLOCK

Yes, that is one of three possible shimming points.  4 o'clock is what mine needed.  I expect some may need the shim at one of the other two posts.

The shim is particularly important during dynamic timing, as the loosened plate is pushed about by the point springs/cam position angle.

This is also the point gap error and directly impacts timing.  Reinstall the 1-4 points, set the gap CONFIRMING GAP IS SET WHEN CRANK IS 90 DEG FROM F1-4 MARKER

Yes, or the largest gap you can possibly obtain during a 360 degree rotation of the point cam.  This is step one for each points set, and the shim should hold/maintain the gap until the three lock down screws are tightened.  Screws loose, shim needed, screws tight remove the shim.

and the 1-4 static time CONFIRMING BREAKER POINT OPENS AT F1-4 MARKER

That is step two, resulting after the correct rotation of the points mount plate.

The marks on the plate are what you align/attend to.  The labels tell you which mark to reference for the operation being performed.  (Tappets or Ignition.)
The 1.4 refers to the cylinders being addressed.  The double marks off to the right are for the range where full advance takes place.

[KeithB]

Thanks TwoTired. makes sense now.
I have been using the F1.4 marks to start the process.

[Spanner 1]

Wait now  ... let's be sure were all on the same page... above you say that on setting the points gap to 14 thou. you are rotating the main plate to try to get the correct gap ?? Completely incorrect , if so .
When setting the points gap, the main ( or sub ) plate does not move.... let's just start over. 

Please do the following easy steps to time your bike....
1. Turn the points cam until 'F 1-4 ' appears in the 'window'. Ignore the points, plate screws etc.
Now, continue to turn the points cam 90 deg. past this 'F 1-4' mark. Stop here.
2. Loosen the single point screw ( has an adjustment slot under it ) and with a straightedge screwdriver move the point faces away or towards each other until a 14 thou. feeler gauge just slips thru'. Tighten screw.

Repeat step 1. except using 'F 2-3 ' marks.
Repeat step 2. except using "F2-3' points.

Now turn the points cam ( always clockwise ) to the 'F 1-4 '. Stop here. This is the exact place the 1-4 points need to be just opening and 'fire'..... Loosen the 3 main plate screws and turn the main plate left or right to achieve the points opening. You will need a test light ( with ign. 'on' ) or an ohm-meter ( ign. off ) to see the exact moment the points open. Tighten the 3 main plate screws.

Turn the points cam to the 'F 2-3 ' mark. loosen the 2 sub-plate screws at the 2-3 points and turn the plate to the left or right to achieve points opening..... tighten screws. Done static timing 

[Plummer]

I just set them by the book at "fully open" Then I set the plate "where the bike sounds good " !!! probably the wrong approach , but it works for me ! I have never owned a light or anything of the sort ! no problems in 28 yrs like that LOL !

[KeithB]

Finally sorted!
1-Went back and started over by first duplicating the high cam mark onto the crank nut so I could align the points open location instead of this 1/4 turn stuff.
2- change gap measurement from .014 go and .016 no go to .015 and .016.
3-Started with the plate located in a full clockwise position.
4-Rotated cam to set 1-4 gap. then rotated to set 2-3 gap.
5-Using ohm meter continuity setting, moved the plate to get 1-4 firing location. Then moved sub plate to get 2-3 firing location.
6-Re-checked high cam gap on both.
Kept repeating 4-5-6 until I could get firing on 1-4 and 2-3 exactly where it is supposed to be.
Spanner, just read your post now but ,yes, that's how I was setting the gap. Not by rotating plate.
Verified with strobe.
All good!
It's the questions and comments from all of you that got me to re- think and solve this issue.
Many thanks to everyone who helped
Now that I know how to do this and the PITA that it is...I'm off to buy a Dyna S module.

[grcamna2]

I think the reason it's difficult to set the points w/ 1 quick shot AND then go for setting the timing after that is the problem with the fit of the breaker plate assembly in the cases.When the 3 screws are loosened up to do the final timing setting, there is movement at the breaker plate from the pressure of the points springs which moves the entire breaker plate around to change the points gap.I see now why shimming the breaker plate on one..or more of the 3 breaker plate screw posts becomes necessary to do to get the non-precision manufactured breaker plate assm.(which is a bit different shape from one manufacturer of points to the next)to sit exactly(you never really can get it "exactly" centered ) centered on it's 3 mounting screw posts. I want to find a way to get mine as close to centered as humanly possible.. , and then shim it and try to keep those same points in there w/ the shims as long as possible. I want to hook up my HM ignition soon so I won't have to adjust them much more once set up Nice  .

[seanbarney41]

Finally sorted!
1-Went back and started over by first duplicating the high cam mark onto the crank nut so I could align the points open location instead of this 1/4 turn stuff.
2- change gap measurement from .014 go and .016 no go to .015 and .016.
3-Started with the plate located in a full clockwise position.
4-Rotated cam to set 1-4 gap. then rotated to set 2-3 gap.
5-Using ohm meter continuity setting, moved the plate to get 1-4 firing location. Then moved sub plate to get 2-3 firing location.
6-Re-checked high cam gap on both.
Kept repeating 4-5-6 until I could get firing on 1-4 and 2-3 exactly where it is supposed to be.
Spanner, just read your post now but ,yes, that's how I was setting the gap. Not by rotating plate.
Verified with strobe.
All good!
It's the questions and comments from all of you that got me to re- think and solve this issue.
Many thanks to everyone who helped
Now that I know how to do this and the PITA that it is...I'm off to buy a Dyna S module.

actually, this all gets to be very easy with a little practice...you will get to start with your new Dyna because you set the timing in pretty much the same way

[TwoTired]

Finally sorted!
Now that I know how to do this and the PITA that it is...I'm off to buy a Dyna S module.

Oh, come on.  Now that you know how, is it really that difficult?  Besides, you only do it once every one-three years!
I can find lots better things to spend that money on than a Dyna.

Once you learn the secret handshake, must you cut off your hands? 

[lucky]

Lucky,
Yes, new points.
Using the light bulb method as indicated in Clymer manual. Confirming with strobe, again as indicated in manual.

I would like to verify what each set of marks is for. It's not like these manuals are always correct.
From the pic in my OP there are 3 sets of marks at the top.
From the left is "TI" then "FI1.4" then "II"
What do you understand as the use for each one?

Just use the F mark. It is supposed to fire between the two marks,
The shop manual should make it very clear.

[lucky]

Lucky,
Yes, new points.
Using the light bulb method as indicated in Clymer manual. Confirming with strobe, again as indicated in manual.

I would like to verify what each set of marks is for. It's not like these manuals are always correct.
From the pic in my OP there are 3 sets of marks at the top.
From the left is "TI" then "FI1.4" then "II"
What do you understand as the use for each one?

The manual is correct on this.

[TwoTired]

I think the reason it's difficult to set the points w/ 1 quick shot AND then go for setting the timing after that is the problem with the fit of the breaker plate assembly in the cases.When the 3 screws are loosened up to do the final timing setting, there is movement at the breaker plate from the pressure of the points springs which moves the entire breaker plate around to change the points gap.I see now why shimming the breaker plate on one..or more of the 3 breaker plate screw posts becomes necessary to do to get the non-precision manufactured breaker plate assm.(which is a bit different shape from one manufacturer of points to the next)to sit exactly(you never really can get it "exactly" centered ) centered on it's 3 mounting screw posts. I want to find a way to get mine as close to centered as humanly possible.. , and then shim it and try to keep those same points in there w/ the shims as long as possible. I want to hook up my HM ignition soon so I won't have to adjust them much more once set up Nice  .

Well, as I see it, you never really have to replace the main plate...ever.  You can replace just the points that sit upon it.  So, what can be done, is to make the plate you have fit exactly into the post mounts for the bike you have.  It will be custom fit to just that bike, but so what?

Here is one method for making that custom plate fit.  You just need a flat face hammer and a flat anvil.  Locate/mark your plate where it engages the posts.  Peen or flatten the metal plate on the anvil in the areas where it interfaces with the posts.  This action expands the metal, and the idea is to expand it so that all the play is taken away from the fit tolerances manufactured into the plate, and essentially gives you a zero clearance plat upon which to mount your point sets.  This is nice as you don't need to deal with shims anymore, and if you want to use a dynamic timing light, for adjustment, loosening the screws won't allow the springs to move the plate around laterally in the mounts.

Cheers,

[grcamna2]

I see what you're saying TT..only how will I be able to know just how much flattening  to do to get the plate exactly centered along each slot?  also, once I flatten just the edges of the breaker plate..will the hold down screws be able to keep a good grip to hold down even that flattened section along the edges? I imagine that I don't need to tighten them down way too much...,but I still like the idea of the shims. I may have to go through the shimming process again if I was to strip out one of the points hold down screw threads in the points plate.
I do see the benefit of flattening the edges of the points plate along those 3 slots to get it centered so when I rotate the base plate, the points gap will stay constant...I'm just not sure if I will be able to flatten it just right to accomplish that.

[KeithB]

Secret handshake! LoL!
Too many hands to shake...still gonna by a  Dyna.
Value of money spent is relative...and it's relatively certain I ain't doing points again
BTW..I did take the points off and see what play there was in the plate. Nada.

[grcamna2]

KeithB,
    Does the Dyna have an extended warranty ? the HM ignition has a 5 year warranty.

[KeithB]

The Dyna DS1-2 just replaces the points and doesn't carry a 5 year warranty. However, it's a very simple crank sensor system and not much to go wrong.
I  know there is some opinions about how well it works at high RPM but I installed one on another CB750 and it worked great.
The HM system uses some electronics and probably works very well to high RPM, and the warranty is very generous.
But still...gotta fiddle with the points.
I'm of 2 minds in that now I have the points figured out, maybe it's not so bad and I'll just stick with them and not spend the $$.
However, other times I have done something like that, it has come back to bite me in the ass and I wished I had just spent the money and dealt with it.

[lrutt]

Secret handshake! LoL!
Too many hands to shake...still gonna by a  Dyna.
Value of money spent is relative...and it's relatively certain I ain't doing points again
BTW..I did take the points off and see what play there was in the plate. Nada.

Good thing you don't own an old brit bike then. Both my old Triumphs, my Norton, my Guzzi, my 305 Dream, and both my 750 SOHC's all run points. I will never convert.

My son was of the same opinion. He was determined to get rid of his points on his 550 against my advice. He did, fought that EI POS for a long time before putting points back in and having a fine running bike. Still doesn't want to admint the old man knew better.

[grcamna2]

The write up on the HondaMan ignition is true.

[KeithB]

While I understand the operation of the HM ignition and have no doubt that it works just fine, using one would just add more parts than reduce.
Somewhere down the road in another 10 years ,I or the next owner, might have to deal with an electronic failure.
Just to clarify, what I am installing is not an electronic ignition but a replacement for the points only, that uses magnetic actuated switches.
While it is called an "electronic" ignition, it is actually a "passive" device.
I installed a Dyna DS1-2 on another CB750 and it worked just fine. Timed easily, stayed timed and removed the points.
7 bikes with points! Your Kung Fu is better than mine!
My other 3 bikes are pointless (joke?) as they have stock electronic ignitions, and I'm keen to make this one similar.
In the end I did come out of this knowing how to properly set CB 750 points and that's a good thing to learn.

BTW...kids will never admit the old man was right 

[Bootlegger56]

I kinda like setting points and timing on these bikes.  Its almost as good as meditation and my anger management coach Dr. Worm tells me she has seen noticeable improvement since I started playing with my "Honda Toy!"

[TwoTired]

I installed a Dyna DS1-2 on another CB750 and it worked just fine. Timed easily, stayed timed and removed the points.

I almost fell prey to the Dyna sales hype, but I was able to resist the dark side back in the 80s, and avoided that barely adequate product.
After I saw the Hondaman analysis of the Dyna-s operation, I really felt proud of myself for such personal fortitude.   

You see, with original points/points cam, the coils are only allotted power for 190 degrees of crankshaft rotation, while the Dyna-S drives coil power for 330 degrees of crank rotation.
So, for whatever coil you use, the Dyna forces 57% more power to be used by the ignition system.
The CB750's 210 watt alternator usually has this to spare, along with a 14AH battery, and can cope with adding a piggy electrical component or two. 
The CB350F, CB400F, CB500, and CB550 only have, 150 watt alternators and 12AH batteries.  The added power draw places them much closer to the edge of acceptability, and demand that the entire charging and electrical system be working at max efficiency.

Did I mention the coils will run hotter, fail sooner when dissipating those extra watts, particularly in hotter climes?
Did I mention that the spark voltage/current will be exactly the same as with points, unless you increase the spark plug gap?

Still, some feel the "convenience" of not utilizing knowledge and the small effort to maintain points is worth paying for a poorly engineered product.
Don't feel bad about buying or owning a Dyna-s, though.  You're in the same company as those many buyers of Pintos and Corvairs attracted by that "new" and "modern" smell.  /jk 

In case you are wondering, yes, I do have a grudge against Dyna !  As I do against any poorly engineered product made popular by clever advertising, and mythical folklore, rather than bona-fide technical merit.
It's actually rather a pity, as they got the reluctor trigger portion of it right, then stopped the electrical engineering to make sales a priority, and cash in on half the work they did right.

But, that's just my opinion, of course. 

Cheers,   

[grcamna2]

I kinda like setting points and timing on these bikes.  Its almost as good as meditation and my anger management coach Dr. Worm tells me she has seen noticeable improvement since I started playing with my "Honda Toy!"

I'm considering going to see Dr.Buddy Rydell for Anger Management..,if he's good enough for Adam Sandler,he "may" help me enjoy life a bit more also 
But please don't quote me on this... .

Edit: no disrespect intended Bootlegger...I just couldn't help it;That movie had me in stitches for hours LOL 

[BobbyR]

My Dyna is in the trash as are many others, while they have little to fail, what little they do have fails.
I went PAMCO. I have fiddled with points all my life. I will spend what is left of it not laying on the floor gapping and timing.

[KeithB]

It's interesting that the trigger has worked well in the other CB 750 and has worked for quite a few years in my buddys CB750 but I guess time will tell.
 I suppose I will just have to wait and see if I have made a bad decision as it is mine to make. I promise not to come back and complain
While trying to keep the '72 CB750 as stock and period correct as possible, the points just beat me down!
" I will spend what is left of it not laying on the floor gapping and timing." My sentiments exactly.
If I do another CB 750 project, I will certainly look into HM or PAMCO products.

BTW...TwoTired...I have read a number of your posts and respect how you back up your POV with a detailed technical argument instead of trotting out bull #$%*.
However, making personal comments about your contempt for people (that would include me) that purchase this product does nothing to support your technical POV and are unwelcomed.(at least by me)

[BobbyR]

Keith, you may not have made a bad decision. Dynas were bullet proof for a long time and then supposedly made some changes and they ran into problems. The new ones may have it sorted out and you will have no problems.