Half of a DYNA-S for the KZ750 Twin

If you’re like me, you’ve heard about people using a DYNA-S DS2-2 (by DynaTek) Electronic Ignition — meant for KZ550/KZ650 four-cylinder — on a KZ750 Twin.  I’ve been wanting to do it for a long time, but between my two 750s, my Newtronic has been rock-steady on one bike, and the points have been good for ten years on my other bike.  Well, it came time once again to adjust the points, and I decided that meant it was time to eliminate the points and finally try the mod.

1-DynaSInBox

DYNA-S DS2-2 In Box

So I ordered the DYNA-S from z1Enterprises.com, and as you can see in the picture of the contents, I ordered an extra rotor too.  Why?  Well, because I have two twins, and if it goes well, I intend to use the other half for my other 750.  The guys at z1Enterprises.com explained that they keep extra Dyna parts on hand for these type of special requirements, so it was no big deal to add that to my order.

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Dyna-S Box Contents

First I had to disassemble the pickups from the rotor, since first one needs to be relocated, and the second isn’t needed.

4-StartingDisassembly

Pickup & Plate Disassembly (1)

Here it is, all apart.  Note the hole locations.

5-Disassembled

Pickup & Plate Disassembly (2)

Gently beginning the slicing apart of the protective wraps and coatings.

6-Separation1

Twin Separation Surgery (1)

A bit like Siamese twin surgery, as I work to separate the halves.

7-Separation2

Twin Separation Surgery (2)

Gently making my way along the length of the outer wrap, careful not to damage the inner wire wrap.

8-Separation3

Twin Separation Surgery (3)

Finally, the outer wrap removed and set aside (for reuse later).

9-Separation4

Twin Separation Surgery (4)

Here they are, un-intertwined.

10-Separation5

Twin Separation Surgery (5)

Here are the old points & condenser, before removal.

3-OldPoints

Old Points

Here’s the auto-advancer, after points plate removed.

11-PointPlateRemoved

Points Plate Removed

Then, remove the cylinder from the advancer.

12-AdvancerCylinderRemoved

Removing Auto-Advancer Cylinder

Lubrication.

13-OilAdvancerShaft

Lubricating the Advancer Shaft

Now, the Dyna rotor goes in.

14-InstallRotor1

Installing the Dyna Rotor (1)

Open the advancer legs to insert rotor.

15-InstallRotor2

Installing the Dyna Rotor (2)

Finally, the rotor in position.

16-InstallRotor3

Installing the Dyna Rotor (3)

Checking for closed.

17-InstallRotor4

Installing the Dyna Rotor (4)

Checking for open.

18-InstallRotor5

Installing the Dyna Rotor (5)

Now installing the Dyna plate over the rotor.

19-InstallDynaPlate

Installing the Dyna Plate

Remember the sheathing we removed earlier? You can re-use it here if you don’t have something else to use.

20-ReuseSheathing

Reusing the Sheathing (1)

I used Liquid Electrical Tape along the length to re-seal the sheathing.

21-ResealSheathing1

Reusing the Sheathing (2)

You can see how I just followed along the seam, closed it up, and waited until dry.  *IMPORTANT*: Note where the pickup is mounted.  It is using both BOTTOM mounts, where both of the pickups were previously mounted.  I didn’t have to tap any new holes or anything.  Your results may vary.

22-ResealSheathing2

Reusing the Sheathing (3)

Here is the freshly-trimmed wire ready for connection.

23-TimingWire

Timing Wire

To quote KZRider.com forum member “loudhvx” from a recent post on the subject:

…you will time it the same way you would with points, but using voltage instead of continuity.

With ignition power on:
With a voltmeter on the negative side of the coil, that is the side the Dyna S is connected to, it should read low, near 1 volt or so, when the magnet is away from the pickup. Then it should read battery voltage, around 12v, when the magnet is aligned with the pickup.

Rotate the crank the opposite direction of the wheels (front and rear wheels of the bike) , so that the meter goes from 1v to 12v just as the F mark lines up with the pointer on the engine case. Adjust the position of the pickup as necessary to get that to happen.

Be aware, the coil is heating up anytime that voltmeter shows around 1v. Try to get the crank into a position so the voltage is 12v. That will let the coil be at rest. You don’t want to cook the coil. So turn the power on when you think the magnet is lined up with the pickup. Make sure the spark is able to discharge. That means have the plug wires hooked to the plugn in the engine, or at least make sure there is a path for the electricity from one plug wire to the other. If not, you can damage the Dyna S or the coil.

 

24-SettingStaticTiming

Setting Static Timing

And here’s me doing the static timing to get started.

The provided Dyna instruction also offer guidance for dynamic timing (Step #7 of “Timing Procedure”):

The engine can also be timed dynamically using a strobe light in the normal manner. Use the advance marks and an engine speed of about 2500 RPM (full advance).

 

25-SettingDynamicTiming

Setting Dynamic Timing

Now after it is started, use the strobe to dial it in.

26-FinalPosition1

Final Position (1)

Here it is in the final position.  And running perfectly.

27-FinalPosition2

Final Position (2)

So can it be done?  And does it work?  Yes, it did for me.  No guarantees, I just wanted to try it.  If you want to toss your money at it go ahead.

..and, you may have noticed in the pictures that I actually installed both pickups just to experiment if there was any difference, and no there isn’t.

By the way, one P.S. here… After this mod, I noticed that the bike was much more dependent upon good ground and good power than before.  With points, I could get away with my old wiring, but once I did this mod I had electrical stalling issues.  Once I cleaned up all my grounds and fixed some power lines, it seemed to solve the problem.  Just a warning, that you probably shouldn’t do this if your wiring isn’t pristine!

I hope this helps!

10 Comments

  1. Laurie

    Hi all,
    I have read in other installation reports that you have to remove one magnet from the rotor.
    At a guess I would say that as it is configured for a 4 cylinder that you will get a double spark, , one at TDC and one at BDC as well.
    Has anyone done this before, i.e removing the magnet or does it not present any problems having the “wasted ” spark.
    Considering this is only a rarely used bike for classic runs I suppose it wouldn’t hurt.
    I intend to do this on my “77 KZ750B ( only 8000 miles )
    All comments welcome.Cheers
    Laurie
    Melbourne
    Australia

  2. Perry

    I’m in the process now for my 78. Which direction did you point the magnet on the Dyna rotor? It can be installed 180° off.

  3. Biquetoast (Post author)

    @Perry – I gotta admit, I didn’t think about it at the time, and I don’t remember now. Give it a try, you have a 50/50 chance! 😉

  4. Perry

    Come to think of it, it shouldn’t matter since it’s a 180° engine right? Wasted spark and all.

  5. Biquetoast (Post author)

    @Perry – Well… technically… it’s a 360° with wasted spark, but there ya go… 😉 -‘Toast

  6. Perry

    Follow-up: got the Dyna installed. No issues at all, bike runs great, very fun to ride the twisties.

  7. Biquetoast (Post author)

    @Perry – Awesome!!

  8. Laurie

    Hi All,
    After much delayed start , I am finally fitting the Dyna to my KZ.
    The Dyna rotor is really sloppy on the point cam shaft. The OEM points cam is quite a nice sliding fit. Is this a problem.
    Also can’t seem to open all the pictures on the fitting of the Dyna.
    It gives me this :
    “Sorry, the parameters you provided were not valid”
    Any ideas anyone.
    I did work last week when I started the install, should have printed it.
    Computers …ahhhh!
    Thanks
    LJ

  9. Biquetoast (Post author)

    Hi LJ – The pictures issue might be because of the firewall protection I run on the site. I get soooo much spam and hack attempts that I have to rate-limit the site and the pictures and stuff in it, sorry. So it might be that it just thinks you have transferred too much of the content in too short of time, and it will let you do it again later. Sorry about that. I’ll try easing up on the parameters… I just checked and all the picture are still there, so at least that’s something. As for the dyna rotor being “sloppy”, I can’t recall but the picture makes it look like a perfect fit….

  10. Laurie

    G’day Biquetoast,
    Ah! the Internet.
    I have been talking to Matthias at Dynatek about the sloppy rotor, but they could shed any light on the issue.
    I see in another post someone had the same issue.
    I machined up a bronze bush that i pressed onto the OEM point cam shaft and then machined it again for a very nice sliding/rotational,just like the Kawasaki point cam.
    I’ll put up a picture of the finished product ( if I can just work out how.)
    back to the Dyna Install.
    All the other pics on your forum appear, but not the one with the Half a Dyna.
    Any chance you can send seperately to my email address.
    Pictures are so good when doing stuff like this .
    Cheers
    LJ
    melbourne

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