TCI Replacement 2020 It Works

After playing with test stand connected to the scope I went back to the screen shot of the GN manual and I'm convinced that they are describing a analog TCI. These newer boxes are programed to match the initial advance and total advance of the older boxes.
I base that on looking at the fact that there are 3 distinct advance bands vs the smooth climb I see on the gonzos.
 
Not sure it's worth the time, but it seems to be a crap shoot as to which type of Gonzo you get when ordered so I thought I would help fill in the "where and who did you buy ti from?" question, I taken Yamadude's list and added the where and who I got it from.

Jeff, 4 boxes........................... all are grounded.
Steve has 1 box (dissected)...... grounded.
Jack, 2 boxes............................ Floating
Jim has 1 box........................... grounded.
Jim has 1 box (dissected)... ....... floating.
Thuban, 2 boxes.........................grounded
Jake650 1 box............................floating
Floater: Ordered May 21st from Amazon sold by seller Suuonee
 
I just checked both EBay sellers, Ideals 100 and le_j184 (items I received yesterday):
They (floater and grounded) indicate the same data:

Feature:
  • Adopted to condenser diode ignite. Simplifying the structure of the magneto, reducing costs and improving ignition efficiency.
  • Delicate design, saving space and easy to install.
  • High quality material ensures excellent performance.
  • Original standard, direct replacement for the original one.
  • Especially designed for Suzuki GN250.

Specification:
Condition: Brand new
Material: Plastic
Color: Black
Size: Approx 8 * 5 * 2.5cm/3.15*1.97*0.98in
Package Weight: Approx 156g
Fitment: For Suzuki GN250

Interestingly, they were shipped from the same address.
 
Jeff, 4 boxes........................... all are grounded.
Steve has 1 box (dissected)...... grounded.
Jack, 2 boxes............................ Floating. Amazon sold by seller Suuonee.
Jim has 1 box........................... grounded.
Jim has 1 box (dissected)... ....... floating.
Thuban, 2 boxes.........................grounded
Jake650 1 box............................floating
Floater: Ordered May 21st from Amazon sold by seller Suuonee
 
That same GN250 Unit sells for 49 Euros in Poland:
https://www.motor-x.com/loncin-300-gn250-ignition-module,p.html
Some markup....

But the interesting thing to me is both units actually have an ID/Batch number printed on the plastic casing. To me this is suggestive of a better quality build and of course this comes with a higher price.
 
I think the chinese scooter connection is the reason that these are available. A manufacturer geared up to build these for Loncin in large quantities. They probably build the GN engine under license like the Honda horizontal engines.
 
My first test of the Gonzo involved my '83 Heritage Special.
Post #631:
http://www.xs650.com/threads/tci-replacement-2020-it-works.57388/page-32#post-651892

Today I connected 3 of my 4 Gonzo boxes to my '82 Heritage Special.
The connector is wired the same as the '83.

GonzoTest2 004.JPG


The '82 has been thoroughly overhauled and the charging system is strong.

Results are the same for all three grounded boxes: It starts and idles OK, but does not accelerate well; it stumbles, coughs and pops horribly from 1.5k to 3k.

I disconnected the regulator/rectifier, and found some improvement:
When I roll on the throttle slowly, gradually, it revs pretty good with no issues. I took it to 4k on the centerstand.
However, when I throttle it quickly, it coughs, sputters and stumbles to a moderate extent from about 1.5k to 2.5k, and then it will rev beyond 3k just fine.

Any ideas?
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What does the timing look like ?
With the OEM TCI, the timing was spot-on normative.
The timing was so disrupted with the Gonzo, I didn't take many specific notes, altho I can say that the idle was just a tad advanced from the TCI.

I suspect you may have to swap the pickup wires.
With the assistance of Jim, we determined that these boxes are grounded units.
So, is swapping the pickup wires really indicated?
 
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One other thing I discovered is that the timing changes with resistance of the circuit. Not sure what causes it. Maybe check your pickup circuit resistance with the box unplugged. I did find the grounded boxes were polarity sensitive. With it the wrong way the timing was advanced and erratic on the test stand.
 
Looks like from Jim's experiences that swapping the pickup leads may be required on one of the flavors of boxes I'm still not clear on which. Is the box on the 83 a floater?
Thanks for your feedback, Jack.
All four of my boxes are grounded, including the unit on the '83.
They appear to be identical, giving the same exact ohmmeter readings.
I'll give you my meter numbers in about 24hrs or so; I'm going to be incommunicado for a bit, while i wander about on two wheels :bike:
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The resistance I'm concerned about is in the wiring to the pickup. Just a shot in the dark.
The other variables is the pickup and the magnet.

1982-83 Should be the same pickup and magnet.

I can say for sure that the stock TCI magnet and pickup are not over powering the input to the box. The voltages on the test stand are higher.
I'm wondering if it's a weak signal that is causing the issues.
A video of it running with a strobe on it would help.
 
The resistance I'm concerned about is in the wiring to the pickup. Just a shot in the dark.
The other variables is the pickup and the magnet.

1982-83 Should be the same pickup and magnet.

I can say for sure that the stock TCI magnet and pickup are not over powering the input to the box. The voltages on the test stand are higher.
I'm wondering if it's a weak signal that is causing the issues.
A video of it running with a strobe on it would help.
I tested the pickup on my '82 Heritage Special.
I'm getting 760 ohms, which is within the 10% parameters.

After a 4 hour ride in the mountains yesterday, my lower back is a bit sore,
so the video of the gonzo timing on this bike will have to wait just a bit.
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Installed my Gonzo #2 (of 4) into the '82 Heritage Special today.
Did this to minimize independent variables in this experiment, as the #2 GN box was the item that ran perfectly in my '83, just like the OEM TCI.

[The '82 had been running superbly on the OEM TCI.]

Ran the engine longer than I did in my previous test.
It seemed to smooth out a bit over time, but the stumbling/popping did not disappear.

Took it out for a short ride. Accelerated OK, but would cut out briefly at about 2.5K and pop.

Back in the garage, took this video.
Interestingly, in the session that was captured, it happened to run most poorly; the performance of the Gonzo on this '82 has been uneven, but always problematic.

You'll notice the timing jumping about.

Impressions of what might be going on are quite welcome.
I've got a six pack of cold Yuengling ready for the dude who figures this out.
Its in the upper 80's here in Central New York, and I'm on my 3rd.


Note: I did the "timing tweak" on this bike, ie, retarded the timing about 2 degrees.
 
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Put a diode in line with the pickup coil to get rid of the negative peak. My thinking is the negative peak is too close in time after the positive peak from the pickup.
 
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