Programmable advance TCI Replacement

Did ya send a schematic or shall I?

Have degree wheel - will travel......lol
Please feel free to send it all! I'm gonna order a unit from him. He seems very responsive and the fact he is asking for pertinent info builds confidence. Will be interesting to build a timing curve for the XS.
 
Done:

Hello,



There is quite a lot of interest in your product for older Yamaha XS650's, we have a website https://www.xs650.com/ and it is currently a topic of discussion.



The pick-up coil is VR type with output ~10-12VAC and it sit's @ 15* BTDC on the counterclockwise 360* crank.



Attached are two schematics from 1980 and 1982 models respectively.



Best Regards
 
Now, I do not know anything about this new ignition box, but I do know a bit about Ignitech, and I believe some aspects apply for both.
With Ignitech, the sensor signal must occur earlier than the most advanced timing. Say 40 degrees or so BTDC. The timing curve is then made by delaying the primary switching to the desired value.
Isn't the stock TCI timing based on just two pickups, one for low (idle) advance, and the other for high advance? If so, then the high advance may be suitable.
 
Now, I do not know anything about this new ignition box, but I do know a bit about Ignitech, and I believe some aspects apply for both.
With Ignitech, the sensor signal must occur earlier than the most advanced timing. Say 40 degrees or so BTDC. The timing curve is then made by delaying the primary switching to the desired value.
Isn't the stock TCI timing based on just two pickups, one for low (idle) advance, and the other for high advance? If so, then the high advance may be suitable.
Good point and good catch. Just speakin' for myself..... I missed this even though I read it a half dozen times..... Yes, with a dual pickup (our TCI system), this box uses the advance pickup. At least that's how I read it now. It's referring to single cyl.... but a 360° twin would be the same.... it's gonna use the 40° advance trigger.



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Just placed an order for one today. Should arrive by first week in September. Hopefully we'll have at least two people testing and ironing out timing and wiring...shouldn't be too difficult assuming it works as advertised.
 
Yes, the first pickup comes in around 40 to 42 degrees btdc, depending on the placement of the module on the chassis. The positive swing of the pulse, which you need will come in slightly ahead. As to the amplitude of the pulse, I have never been able to accurately measure it, but I am certain it will meet the minimum requirement. A question I have about the programmable part of it... what exactly will you be adjusting on the fly? I only skimmed over their website but it wasn't clear to me.
 
My intention is to set it, tune as needed and forget it. I'm just looking for a good substitute for stock igniter.
 
So I guess you will be replicating the stock advance curve to start with. When you are finished tuning, let us know what improvements/changes you have done. I am always curious about what an improved curve would look like.
 
As Jeff stated, it's not so much about adjusting anything on the fly, but being able to set an ideal timing curve for optimum performance and efficiency. Hopefully once timing curve is identified it'll be a set and forget/plug and play type ignition (assuming it works). Perhaps it'll be another good and maybe cheaper option for no longer available stock TCI units. The Gonzo unit works, and while close, it does not provide the same timing as stock TCI units. For earlier points based bikes I would imagine a swap with later TCI rotor, pickup, and stator, along with some re-wiring, may be another option for an accurate crank fired ignition, especially for those not wanting to go the VAPE route. Could be wrong with my thinking but my inquiring mind is willing to roll the dice here. Also having a 12v tach output is a good option to have. Wrong in my thinking?
 
So I guess you will be replicating the stock advance curve to start with. When you are finished tuning, let us know what improvements/changes you have done. I am always curious about what an improved curve would look like.
Yep, I'll start stock - perhaps a couple degrees conservative. The bike is stock top-end, kibble-white valve train, ~2000 miles rebuild, stock BS34 jetted to 45/145 (some wild JN), Gunn Design pipes (1.75" into 2" header w/cones) & K&N 4" (!). Runs real good throughout with plugs med. brown (little rich and I like it). Hopefully a good test bed.
 
Yep, I'll start stock -
Jeff, I'm sure your ign unit will arrive before mine. I'll install on my bobber build w 1,200 miles since rebuild. Similar setup, stock BS34s. Don't recall exact jetting but I know it is also slightly rich and runs great. Looking forward to trading notes on setup/install.
 
It remains to be seen how quickly I start the install; gotta work-up the motivation and get away from this screen. I'm so busy scurrying down rabbit holes 'round here🧐
 
For future reference... the first pickup (40 deg) is the w/g wire. Second pickup is w/r. The pickup ground is b/w.
Unless the unit you get is an epoxy brick, I would like to know what type of output transistor they use to drive the coil.
 
Unless the unit you get is an epoxy brick
From the description:
Plastic box potted for Electrical insulation, Protecting components from mechanical shock and vibration, thermal shock or moisture.
 
In anticipation of getting the timing setup, can anyone provide data points as to what rpm intervals and related advance the timing should be set at? Thinking full advance would be initially set at 38* to be conservative initially, but at what RPM? I think you can program up to 13 intervals.
 
In anticipation of getting the timing setup, can anyone provide data points as to what rpm intervals and related advance the timing should be set at? Thinking full advance would be initially set at 38* to be conservative initially, but at what RPM? I think you can program up to 13 intervals.
There is a timing chart in the shop manual that you can use for a reference. Upto about 1900 rpm the advance is around 15 degrees. From 1900 upto 3300 approx it advances to 40 degrees. From there on it is pegged at 40.
On the stock tci you can adjust the rpms where the advance starts and stops. The 15 deg and 40 deg start and end points are only adjusted by physically moving where the pickup module is bolted on.
 
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