Gonzo DIY TCI System

Team Junk

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The Gonzo Project
The Gonzo DIY TCI
Electronic Ignition System


For any questions about the Gonzo Box Please post on the development/help thread
gonzo Help and Development
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Status 6.23.20
1980-83 TCI Bikes Road Testing on Several bikes
1970-79 Points Bikes Early Testing Stage
1970-83 PMA Conversion Design Stage


6.25.20 It appears there are more than one design of the GN250 Igniter being sold.
Tests Ongoing.


The XS650 Community owes these guys a beer for testing this crazy thing.
:D Keeping tally of running bikes here:

@Jim: 80SG Direct TCI swap.................................... Runs normally. (grounded trigger)
@azman857 80SG Originally TCI/Pamco................ Runs normally. (grounded trigger)
@YamadudeXS650C 83 Special. Direct TCI swap.. Runs normally. (grounded trigger)
@2XSive 81 Bobber. Direct TCI swap...................... Runs normally. (grounded trigger)

Attached files are the online PDF manuals for TCI Replacement and Points Conversion.
 

Attachments

  • Gonzo Install tci replacement.pdf
    843.8 KB · Views: 908
  • Gonzo Install Manual points conversion.pdf
    5.7 MB · Views: 673
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Design Notes.
Troubleshooting

After connecting the Gonzo Box, hook up a timing light and check that the light flashes and if it does that the timing mark on the rotor is near the F mark on the cover.
If the mark is advanced past the F mark and the bike is hard to start try reversing the pickup leads.

It's being reported we might have two flavors of GN250 Igniters. The polarity of the pickup wires is reversed on one of them.
 
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Team Junk, it took me a bit of head scratching to be confident in the pin out of the Gonzo. I Think this image might help others in the future if you can confirm that it is correct, I'll replace it if there is an error. Installed on a 1981 6-Pin TCI connector.

Gonzon Instal.jpg
 
Outstanding ..and Interesting
But as I can se in the Clymer manual a fex 1978

has ignition timing 15 BTDC at 1200
41.5 BTDC at 3300

as to " Provides 20+ degrees Electronic advance "
also beside the diagram

a text with " 35 degrees "

I would appreciate comments about that -- 5 degrees feels risky and loosing power. .perhaps valve opening when still burning.
I was into this a couple of years ago and looked at small Automobiles ..fex certain 4 cylinder Opel has about
twice the volume as XS 650.
Using only 2 of the 4 pins would do it.
And I have heard of BMW MC riders using car ignition parts but as I recall without the advance function.
There exists also programmable boxes.
I was trying to read about it and understand the code.
Which sometimes was out there on the web
Drag racers nowadays are modifying programs. But I could never get past it.
It is to difficult to understand the code. Even if it is out in some form.
Some even build their own system around a Micro controller ..
And having the possibility to modify the ignition curve.

Perhaps someone here has built something of that sort.
Or installed a Programmable systems was it mega squirt the dragracers used
Not sure
I have seen a lap top behind the driver on a Triumph bike for test riding.
 
Port, your photo is really helpful. To be honest, I'm in that 'head scratching' mode right now based on Team Junk info. I think the two wiring diagrams are correct, but I think that 'adapter' pig-tail verbiage may be what's causing some confusion.....at least on my end. The Pin 1 listed as 'Coil Pwr'...... that seems a bit contradictory. I say this only because the coil is energized by the Red/White wire. The orange wire is what I've normally considered the 'signal' wire.....which others may call a 'trigger' wire. It's the 'ground' connection through the ECU if I'm not mistaken. When connected thru the ECU, it supplies the ground to the coil thus completing the energizing cycle. When the ECU 'breaks' this ground connection, it's just like the points opening. So, the internal magnetic field within the coil begins the break-down cycle whereby the flux field passes over the secondary and generates the HV to create the spark(s). If I'm wrong about any of this, please forgive me, and correct me.

Anyway, Pin 2 'in' is the B+, or battery voltage.....and should be at battery voltage when the bike is turned 'on' and the kill-switch (if still there) is also in the 'on' position. Pin 3, coming from the 'idle' sensor in the crank pickup, is the 'plus' (+) feed from the crank pickup - idle. Pin 4 is clearly and correctly ID's a 'ground'.....and with the bike 'on' as per previously indicated, there should be battery voltage measured from Pin 4 to Pin 2. The cavity defined as Pin 5 is indicated as not being used. So, accepting this, the final cavity Pin 6 is now the 'negative' (-) feed from the pickup. It should be noted that as previously stated in this thread, the polarity of the pickup is critical. Like any coil/magnet generator, the magnet in the rotor passes the same way each revolution of the crank as it passes the pickup. The windings in the pickup define whether one wire becomes 'plus' and the other 'negative'......or reverse. Since Yamaha co-mingles the idle and advance pickup coils in their sensor assembly, the 'common' wire is wound such as having the proper polarity to work with the rest of the electrical system. Hence the white/red wire being 'positive' and the black/white being negative.

Anyway, were it not for a rain storm today I'd have a report on my experience with a 'Gonzo' replacement. With some luck, tomorrow I'll have it wired up and ready to try. I'll report back with my results. But, suffice it to say, I'm extremely grateful for the work Jim and Team Junk have put into this. Because of this, I'll be able to get 2 more bikes back on the road. no titles......but, hey...... thank goodness for Vermont!! Tom
 
but I think that 'adapter' pig-tail verbiage may be what's causing some confusion.....at least on my end. The Pin 1 listed as 'Coil Pwr'...... that seems a bit contradictory.
That's a fair criticism... and I'll own that one. I fixed it.

8 pin rev 1 5-24-21.png
 
Jim, are these plugs available 'commercially' some place, or does one simply have to scavange one off of an old wiring harness? I'd love to make up a pig-tail like the one pictured. As it is now, I'm taking the old N/G (no good) ECU and pulling the wires off the control board so as to make up something 'similar' to what is shown. But, without a 6-pin connector to 'in' to the Gonzo unit, I'm stuck with using individual spade connectors. Not a particularly desirable method......functional, but with perhaps some 'reliability' issues since they're all open to the elements in the gonzo cavity. I was thinking about 'potting' the end of the gonzo once all the connectors were in place......so as to seal it from the elements and provide a bit more secure of a connection termination. But, should the gonzo fail, I wanted to be able to 're-use' the wires/8-pin connector by re-attaching them to another replacement gonzo. The adapter pictured shows 6-pin to 6-pin, and I'd need a 6-pin to an 8-pin if possible, more like the diagram vs the photo.

Thanks Jim!!!

Tom D.
 
Hey all!

Just dropping by to say thank you SO MUCH for this mod. :)

My '82 XS650 Heritage Special is running once again because of you guys!
Here's a link to a video on my channel where we finally get to the bottom of diagnosing the no start issue with my bike thats been in storage for 3 years-
https://youtu.be/0q34Vg7c5MI?si=VKRJB_6ME5TAYZU5

Thank you again!!!!
-BugzyXS
 
You're welcome. Now go ride the wheels off it.
Love those fishtails. :heart:
Just an fyi... there's been a rash of junk gonzo boxes out in the market. As cheap as they are, most people just carry a spare around with 'em.... just in case.
 
You're welcome. Now go ride the wheels off it.
Love those fishtails. :heart:
Just an fyi... there's been a rash of junk gonzo boxes out in the market. As cheap as they are, most people just carry a spare around with 'em.... just in case.
Thank Jim! The fishtails were one of my first upgrades:)

😖 I may have spoke too soon! I've taken her out for about 100 miles of riding since the Gonzo mod... Then when I tried to start her today the battery was dead! ☠️ Has anyone on here had problems with generator issues after installing the mod?

Here's a few notes-
  • It's a new battery by the way and no other electrical issues prior to mod.
  • My bike is a '82 XS650 Heritage Special.
  • Stock ignition system and all that.
  • I did buy a backup TCI but its from the same Amazon seller I got the original one from.

Thanks guys, it's so great to have a place like this where I can share what I'm going through with people that get it!
 
Generator alternator issues are a fairly common problem to these bikes until they're properly sorted. After that, it's as good a charging system as any. So no, not likely caused by the gonzo mod.

The brushes in the alternator are a "wear item." That is... they require periodic replacement. The alternator rotor is the next most common failure point. Here's a link to troubleshooting charging problems. Scroll down to comment #3. Basically the same as the one in the Tech menu, but I've added a bit to it.

I know from your video (well done btw) that there's a new battery in your bike. Unfortunately, new doesn't necessarily mean "good."
Follow the tests in the link below and hopefully that'll lead you to the problem.
Good luck and be sure to ask any questions here in this thread. There's some very knowledgeable and helpful people here.


https://www.xs650.com/threads/rewound-alternator-rotor.54276/
 
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