Points to GN250 Electronic Ignition Conversion

Just to try to clarify, my solution to convert a points bike is to mount a TCI rotor and stator, but use the GN250 ignitor rather than the factory TCI box.
My question was about the wiring changes needed to get an 80 up TCI/generating system to play nice with a points model harness.
The solution seems to change the brush grounding and use the points model reg/rec. I have it to that point.
But the starter safety switch module may need to be switched as well?
It all comes down to the stator. If you modify the existing stator, nothing need be done... it already worked. We didn't do anything to change that.
If you install a TCI stator in a pre-TCI bike, there's a fork in the road...
Upgrade to a reg/rec (type A) and modify the (bikes) wiring accordingly. Or....
Keep the existing regulator (type B) and modify the (stator) wiring.
In all cases, the safety relay is unaffected.
 
Upgrade to a reg/rec (type A) and modify the (bikes) wiring accordingly. Or....
Keep the existing regulator (type B) and modify the (stator) wiring.
In all cases, the safety relay is unaffected.

Modifying the stator wiring would be the nylon screw mod mentioned earlier and I think the connector for the regulator. I don't have any factory wiring harnesses so this is from memory. Not sure if the 2 flavors ( A and B share the same connectors but I suspect not if memory serves.
 
Modifying the stator wiring would be the nylon screw mod mentioned earlier and I think the connector for the regulator. I don't have any factory wiring harnesses so this is from memory. Not sure if the 2 flavors ( A and B share the same connectors but I suspect not if memory serves.
The stator connector is identical pre and post TCI.
The nylon screw mod is to update a pre TCI stator to the post TCI reg/rec standard. You only do that when converting a 79 and earlier to the 80 and up reg/rec (type A)
@lakeview ... tell us what your plans are and I'll give you a diagram of what needs doing.
 
Thanks Jim
My understanding of the GN250 conversion on a points bike is that the stock rotor would need a magnet installed and the the stock stator would need a pickup. From what I have read, a plug and play pick up has not yet been found and besides, one would have to install a magnet on the rotor to activate it.
My solution, prompted by gggGary, is to switch in a TCI rotor and stator, I have a couple spares to work with.
(I am guessing that I could also install the TCI rotor and then modify the points stator to accept the TCI pickup, which may avoid the A or B regulator question, but require me to do precise machine work to install the pick up....)

So to convert my 77D ignition to use the GN250 ignitor instead of points, I am thinking that the way to do it would be to install the TCI rotor and stator, change the grounding on the brushes so I can continue to use the stock regulator, change the coils to a dual coil with a different ohms rating, delete the condensors, points and mechanical advance and wire it so the GN250 box can send signals to the new coil. I know there are threads that describe the plastic screw mod for the brushes and I should be able to follow that, but getting the proper wires from the new ignitor box to the dual coil may be a challenge for me.
I have ordered 2 GN250 boxes from Amazon.ca which were priced at about 17 loonies each and free shipping from China (packages from China seem to come to me without any customs interference or brokerage charges), so once I get them I will compare them to what you innovators have been using. I do not have the Honda coils, but have several spare dual coils from TCI bikes that should work for this application.
Is my description of the job to be done complete?
 
A) TCI dual output coils work fine. The dual output coils on Yamaha 4 cylinder from the 80's all work fine.

B) Using the points sator and cover is the route I suggest. Drilling the holes for the pickup will be pretty straight forward once their placement has been determined. That eliminates having to molest the charging system in any way.

C) I would leave the points and advance flyweights in place. They are not hurting any thing and there is a future possibly of using the points system as a backup.

D) The RX pickup triggers the Gonzo box just fine. In fact I think better than the stock TCI pickup and magnet.

I have three days of rain scheduled so I hope to do some durability tests on my test stand this week
 
E) Only one wire needs to be run for the ignition coil . The stock wire color is qrange and it runs from the Gonzo box to the Coil Negative. The coil positive is connected to the stock points system red/white from the kill switch.

F) Leave the condensers in place but disconnected. Again for a possible points backup system.
 
B) Using the points sator and cover is the route I suggest. Drilling the holes for the pickup will be pretty straight forward once their placement has been determined. That eliminates having to molest the charging system in any way.

If you used the TCI Stater, all that would be needed, is to swap the brush holder over from the B type stater, (70-79) to the TCI, A type Stater, (80-84). no wiring changes or charging system changes.
 
No need to change the brush holder or do the nylon screw mod. The nylon screw mod is for adapting the early '70-'79 stator for use with the later ground switching regulator. You shouldn't have to do anything other than insure the inner brush on your "new" late stator is now grounded full time.
 
OK Lakeview, here's the schematic for the TCI bike conversion pigtail. What you're concerned with is the left connector.... the one that plugs into the GN box.

Pin 1 will go to the neg. side of the dual coil. That's the grounding side.... that would normally go to the points. Note: Most dual coils are not polarity sensitive. What that means is you can just plug power and pin 1 on either of the 2 coil terminals... doesn't matter... will work both ways.

When you remove the old coils, there will be 1 wire coming from the kill switch (should be red/white) that splits into 2 wires and goes to the positive side of both the old coils. 1 of those will go to the pos side of the dual coil, the other needs to go down to pin 2 of the GN connector.

Pins 3 and 6 will go to the trigger coil. When you can, let me know what wire colors you have on your TCI trigger (there's 2 versions) and I'll let you know which ones to use.

Pin 4 goes to a convenient ground point.

Pin 5 isn't used.

Clear as mud? :sneaky:
Ask us questions on what you're fuzzy on (if anything) and we'll clear it up.
You'll need the connector to plug into the box and one to plug into the TCI trigger connector. Those can be had here. Not sure what shipping will be, but his prices are very reasonable imo.... and he ships promptly too.

Pigtail Wiring V2.png
 
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Thanks for the diagram and explanation. Looks straight forward.
TCI trigger wires are black, orange and gray.
 
New carb parts showed up. Put em all in a rt carb body I horse traded for with @RustiePyles . Started the run stand (first time this year) using the factory points setup and did a little tweakin' on the carbs. Shut it down to set up the tripod and camera. That's where this video picks up....


Did 3 or 4 runs after, that I didn't video. It's odd, one time it'll fire up and act like it did in the video and the next time it'll run just fine. Start it up again and it'll be back to poppin' and fartin'. Put the timing light on it and the advance is way advanced like the first box did on my SG. After a half a dozen revs it'll settle down and act more or less normal.
So... the good news is the homemade setup runs. The bad is it's inconsistent.
This run is using the $5 Yamaha RX-Z pickup, modified stator, modified rotor and the GN box. The RX-Z pickup uses a magnet and the rotor has a magnet. I suspect the box doesn't care much for that combination. I'll take the magnet out of the pickup and see what happens. :umm:
S'posed to be stormy the next 3 or 4 days (this spring has sucked). Not sure when I'll get another chance to run it. We'll see. Meantime I'll try and collect my thoughts and add some more useful info here.
 
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