Topic: Are my points too worn out?

[Dimitri13]

I have the plate advanced all the way, but it's still too retarded. (at idle with strobe gun) At this position I can only get it to line up with the 1-4 | | marks. With the plate rotated the other way, it's even further out.

Will Chevy 350 points work on a 74 550?

[scottly]

You have the plate RETARDED all the way..

[Dimitri13]

Ah. Well, if I turn it all the way the other way (advanced I guess), the strobe shows the timing is even further away from the F mark.

[scottly]

What is your point gap at the maximum opening, regardless of actual crankshaft/timing mark position? Are those Diachi points?

[Dimitri13]

The furthest the points will open is about .035". They are Daiichi points.

[Dimitri13]

Odd. I set it to the opposite position one more time and now it's nearly dead on.  It's still slightly to the right of the 1-4 F mark. That means its slightly advanced, correct?

[Dimitri13]

What the hell, I checked it once more and it's back to where i originally stated. Am I missing something?

[TerryK]

Two words and a letter: Dyna S ignition.

[Dimitri13]

Can't really afford it now and I plan on getting hondamans ignition.

[scottly]

The furthest the points will open is about .035". They are Daiichi points.

The points should only be about .014" at the high point of the point cam. The larger gap equals advanced timing. Hondaman outlined how to work around some of the problems with the cheap points..

[Dimitri13]

I know I read that blog post.

But my bad on my previous post, I misread the plate and it was at the same point as it always way. It was at the full advance mark (1-4 ||). The plate is advanced all the way (opposite of the picture I posted).

The 2-3 timing is halfway between the 2-3 F mark and advance timing mark.

Now back to my original questions:

My points need replacing, correct?
Will small block Chevy points fit on a 550? (it will fit on a 750)

[scottly]

Now back to my original questions:

My points need replacing, correct?

They need adjusting, they don't appear to be worn out, but there are issues with that brand.
Will small block Chevy points fit on a 550? (it will fit on a 750)

Who says small block Chevy points fit on a 750?

[Dimitri13]

Someone on the SOHC4 facebook page has said several times that SBC points will fit sohc 750s. Not sure of his forum name or if he'd like me to share his name, so I'll just leave it at that.

[lucky]

Ah. Well, if I turn it all the way the other way (advanced I guess), the strobe shows the timing is even further away from the F mark.

I keep telling you that the advance marks are for the strobe. 2500 rpm.
But if you just do the static timing that is all you will need.


HOW TO TELL IF YOUR POINTS ARE WORN OUT.


IF the gap is set... and the dwell cannot be  brought within limits, it can mean that the phonelic block on the points set has worn down from rubbing on the points cam.
That also means the condensers have absorbed all they can and the condensers should be changed out at the same time.

[phil71]

No way. Totally different hold downs

[lucky]

OK Dimitri13.

I will walk you through this.

FORGET about the two parallel marks at this time.
Only pay attention to the mark next to the F

But get new points and new condensers if you can .
Position the points plate so that the screw securing the points is in the middle of the
curved slot. Tighten it lightly.
Put the crankshaft on mark next to the F. not on F but the mark close to the F.
Now adjust each points set gap to .014thousandths.

Clip your volt ohm meter lead ground to engine case.
Clip the positive lead hooked to ohms scale x 1000 to one of the sets of points.

KEY OFF.

Turn the engine slowly in the normal direction of rotation by hand. Big wrench on the big nut.

When the mark next to the F  starts to get near you will see the meter (if analog) needle swing to infinity. That means the plug just fired.

If you have to... turn the points plate to make sure  the points open when the mark next to the F mark comes up.
Then move your volt ohm meter positive ohms lead to the other set of points and do the same thing, but this time  if the f mark does not line up and is off just a little adjust the points gap on that set of points to make the F mark and points firing to happen. Don't turn the points plate.

IF you start up the engine you want to hook up the dwell meter and make sure the dwell is with in limits. If it is not 46º-49º on each set of points,  then you probably will need a set of points.
You cannot just make the points gap wider to get the dwell in spec because then it will have weak spark.


Thats all you have to do.
If you want to put the strobe on just to see how it looks by all means do it.
But do not turn the points plate. The advance marks have two marks together on the rotating crank. The outside single mark should fall in between the two parallel marks.
The engine needs to be sped up to the advance rpm which is about 2500 rpm.
As the rpm increases you will see the marks start to come into alignment.
If it does not you may need to check your advance mechanism and make sure it is not rusted shut and sticking, or has a broken spring or something ( very rare).

[Dimitri13]

Thanks lucky, that made sense. Looks like I'll be needing new points/condensers. But just to triple-check, I'll consolidate my issues into one post for verification.

Symptoms:

1-4: When plate is set all the way advanced (opposite of the picture in the first post), at 1000 RPM, the strobe light shows the full advance mark (1-4 | |), which means the timing is too retarded. The firing mark (F) was not visible, as it was to the left (counterclockwise) of where the strobe was showing.

2-3: At 1000 RPM, the strobe light shows between the timing marks (2-3 T F) and full advance mark (2-3 | |), which means the points blocks are unevenly worn.

Solution: Replace points and condensers.

Am I correct in my diagnosis?

[phil71]

Lucky, where do you get this stuff? On the 2/3 points you don't vary gap to alter timing , you slide the plate. Just go to the service manual , and do the test light method.

[TwoTired]

Have you read the FAQ about shimming the main points plate?

[Dimitri13]

I will now.

[bollingball]

Two words and a letter: Dyna S ignition.

No it is TEC and HondaMans ign. box

Ken

[Dimitri13]

Isn't TEC just coil and condenser?

Either way I still need to get new points/condenser. I MIGHT get a Boyer when I get a job again.

What brand points/condensers are recommended?

[bollingball]

Can't really afford it now and I plan on getting hondamans ignition.

Dimitri I just did this Go to your Honda shop and get new points Take them out of the box at the counter to make sure they are TEC Save them until you get HondaMans box and put them on at the same time just might be the last set of points you buy. Don't forget new condensers.

Ken

[Dimitri13]

Go to your Honda shop and get new points Take them out of the box at the counter

Haha that may work anywhere else, but this is Hawaii, where nobody carries stuff like this.

[dave500]

youll have to order some,the hondaman ignition will need a good points set up.

[bryanj]

Firstly throw the damn strobe away!!!! You only need one to check if the advancer is working.

Look in the manual and set the timing static with a light bulb---Its cheaper than a dwell box

[Frostyboy]

Now back to my original questions:

My points need replacing, correct?

They need adjusting, they don't appear to be worn out, but there are issues with that brand.
Will small block Chevy points fit on a 550? (it will fit on a 750)

Who says small block Chevy points fit on a 750?

I finally found a reference for those Chevy points, they were used on a system called Maxi-Dwell. Modified points plate.
http://forums.sohc4.net/index.php?topic=31466.0

[seanbarney41]

Dinitri, certain members are giving you some wacky directions in here...+1 on just using a light bulb/12 volt test lamp and using the instructions in the manual.  The Clymer manual actually covers this topic fairly well, and easy to understand.  If you have trouble getting your Daichi brand points to time up, try setting your gap at .012 (versus .014) and try timing again.  Remember, the point gap affects timing so you must always set the gap first, then set the timing.

[bollingball]

Isn't TEC just coil and condenser?

Either way I still need to get new points/condenser. I MIGHT get a Boyer when I get a job again.

What brand points/condensers are recommended?

TEC is the name of the company that makes the points for Honda I think it is (Toyo electric company) They are the good ones. You may still have to shim your plate.
Also if there is a Honda shop on the moon they can get the TEC points.

Ken

[lucky]

Lucky, where do you get this stuff? On the 2/3 points you don't vary gap to alter timing , you slide the plate. Just go to the service manual , and do the test light method.

I was a Honda dealership mechanic for years

If you set the points gap then set the timing by turning the entire points plate
To get the first set of points to open at the right time then you go to set the other set of points by moving the points plate the the first set will be off.

The points gap is interrelated to the time the points open.

[phil71]

I'd agree with you if it were a 350 twin, but the pic of his plate shows the 2/3 move independently. You don't change the timing with the gap. You set the gaps. Time 1/4, then time 2/3 with the ofsets.  It's right in the service manual.

[Dimitri13]

Don't you set 2/3 timing by moving the plate the points are mounted on (the smaller plate off to the right, not the large plate everything is mounted on)?

[TwoTired]

I'd agree with you if it were a 350 twin, but the pic of his plate shows the 2/3 move independently. You don't change the timing with the gap. You set the gaps. Time 1/4, then time 2/3 with the ofsets.  It's right in the service manual.

+ 1

While changing the gap will change the timing, that's NOT how to adjust for proper timing.  (Horses usually pull the cart rather than push it.)  The point gap (and point cam profile) determines the coil charge time.
After setting the correct gap, the plate is moved around the crank to adjust the proper firing angle/time.  1.4 it adjusted with the main plate. 2.3 is adjusted with the 2.3 points sub plate.

No mechanic (I don't care where they worked) has the ability to change the laws of physics.  The Service manual and the Owner's manual, have it right.

[phil71]

Lucky, what's even more confusing is, you ride a 500 or 550 , don't you? Same points plate..

[lucky]

Don't you set 2/3 timing by moving the plate the points are mounted on (the smaller plate off to the right, not the large plate everything is mounted on)?

Yes. Sorry for the confusion. I am sure you noticed that smaller separate plate
for the second set of points.

You know if I make a mistake on this forum they will eat me alive like a pack of dogs.

Maybe I should have just let you figure it out by your self.

[lucky]

Lucky, what's even more confusing is, you ride a 500 or 550 , don't you? Same points plate..

  No, I do not own a 500 or a 550.

[phil71]

Don't you set 2/3 timing by moving the plate the points are mounted on (the smaller plate off to the right, not the large plate everything is mounted on)?

Yes. Sorry for the confusion. I am sure you noticed that smaller separate plate
for the second set of points.

You know if I make a mistake on this forum they will eat me alive like a pack of dogs.

Maybe I should have just let you figure it out by your self.

actually.... he pretty much did

[Dimitri13]

My bad guys, I was setting the point gap improperly. Both my manuals said "when the points are fully open," which I thought meant on the firing mark. I busted out my timing light and found that the points started to open WAY before the F mark, which conflicted with the timing light method in both manuals.

I adjusted the gap while the points were ACTUALLY fully open, and now I have proper timing (I actually had to retard the plate almost to the limit to get the 1-4 timing dead on). Checked with strobe gun, and 1-4 is nearly dead on, and 2-3 is dead on.

NOW I can finally sort my carbs. They need it too, because 1/8-1/4 throttle is absolutely dreadful, I won't get ANY RPM increase and it'll stumble like a drunk. After 1/4 throttle though it just RIPS. Smells super rich, so I'm going to take off the stack screens and see if it gets better.

Thanks lucky, TT, HM, phil, and everyone else who put up with the drama I caused. Important thing is I learned something!

[lucky]

Dimitri13 taking the velocity stack screens off is not going to help the stumble.

I knew this was going to happen.

After you get your points and timing straightened out, then the jetting is still going to need to be straightened out.