TCI Replacement 2020 It Works

[Jim]

Should have added... when I set the bike up last year, I set the timing 2-3° retarded. Yeah.... I've holed pistons in days past. Call me more cautious these days.
Anyway... keep that 2-3 ° retard in mind while watching the videos.

 

[Team Junk]

So runs 2 and 3 which box on which runs?

 

[Jim]

So runs 2 and 3 which box on which runs?

All 3 vids are the GN250 box.

 

[thuban]

( Being it's an Otto and not Brayton cycle) I don't know why the GN250 would be different, advance wise? ( I prolly ought to check out the 250 engine. It's not 4 valves per cylinder?) Cause I don't know. But the advance shouldn't run to 40 ish and drop back to run in the 20ish range. Bad box? I don't know. I'm not close to having the 81 run on a stand, even if I had a Gonzo. ( worrying about making hay now that the rain has quit for several day...until I cut some!)

Edit: could the pickup on the 250 be that different?

 

[GLJ]

Made a template for a 35-40° advance range. Transferred that to a spare pointer I had and to the stator. Drilled and tapped the stator.... put it all back together and here's the videos. I'm gonna spend some time trying to get some good screen grabs but here's where we're at right now. I suspect I have a bad box. Yeah.... 15 bucks from china and I expected it to work fine.... go figure.
When you first fire it up and rev the bike, the advance is well north of 40°.... maybe 45-50°? I'll try and pin it down on the grabs. After 30 sec. or so it settles down to what looks like maybe 10-15° advance. Like I said, I need to get some grabs... you guys can join in on that front too. I'll comment more when I know more. As It stands, I'll prolly wait 'till someone else gets one running to see how their box behaves. I'm hoping it's just a fluke and I just need to order a new box and send this one back.

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Jim
As I mentioned in a earlier post I wondered about the quality of the modules.
But I wouldn't condemn them yet. My experience with timing lights is the higher the RPMs the less reliable. Even Snap On. Take it out and test ride it. You'll know if it's over advancing. Set the timing on many cars by ear.

 

[Jim]

OK, had Sue come out and hold the camera. Worked much better than the tripod. Also pulled the footpeg and shifter out of the way. Bike was cool so you can clearly see the advance go bonkers 'till it warmed up (first 10 seconds or so). After that, looks to be 30-32°. If I take the 2-3° retard out of it, looks like we can get the magic 35° we're shootin' for.

 

[Team Junk]

Ok
I'm wondering if the box is doing adaption on fly with the pickup timing. Looks like it is working great after the hiccup during warmup.

 

[Jim]

Ok
I'm wondering if the box is doing adaption on fly with the pickup timing. Looks like it is working great after the hiccup during warmup.

Yeah, I'm starting to think the same thing. If only someone else had one runnin' for comparison....

 

[Team Junk]

I suspect noise on the signal lines from the stator magnetic field. Box adjusts til it's happy with the signal. I didn't see this behavior on the test stand. Perhaps a magnet transplant.

 

[Jim]

I suspect noise on the signal lines from the stator magnetic field. Box adjusts til it's happy with the signal. I didn't see this behavior on the test stand. Perhaps a magnet transplant.

I doubt it. The magnet is plenty strong on that rotor. On my bike, killing the alternator is simply a matter of unplugging a relay. I'll run it tomorrow without the alternator and see what happens.

 

[TwoManyXS1Bs]

Man, late to the party again.
Great work Jack & Jim. (The JJ gang)
Well done on this project.

...I don't know why the GN250 would be different, advance wise?

The GN250 head is a central-plug pentroof design.


This design uses less ignition advance compared to older designs; wedge, hemi, ...etc.

15° - 35° BTDC, or even 17° - 37°, should be fine on the XS650, considering the modern crappy gasohol has a faster burn. Fine-wire or Iridium plugs may help here.

Been chasing/researching this same modern ignition timing setup on my Vic Vegas, with its same 4-valve, central plug, pentroof heads. Too much advance on these at WOT must be avoided...

 

[TwoManyXS1Bs]

For Thuban.
Member Sleddog83 was reverse engineering the TCI boxes last year, posted some schematics showing the trigger inputs, capacitor isolated. May be of interest...

http://www.xs650.com/threads/other-ignition-options.55310/

http://www.xs650.com/threads/83-heritage-special-tci-troubleshooting.54852/

http://www.xs650.com/threads/12-03-igniter-schematic-ver-2.56146/

http://www.xs650.com/threads/12-01-igniter-schematics-ver-1.56147/

 

[thuban]

For Thuban.
Member Sleddog83 was reverse engineering the TCI boxes last year, posted some schematics showing the trigger inputs, capacitor isolated. May be of interest...

http://www.xs650.com/threads/other-ignition-options.55310/

http://www.xs650.com/threads/83-heritage-special-tci-troubleshooting.54852/

http://www.xs650.com/threads/12-03-igniter-schematic-ver-2.56146/

http://www.xs650.com/threads/12-01-igniter-schematics-ver-1.56147/

Thanks, 2many! I'll read through them!

 

[Team Junk]

Miss having access to blue gas. Would be just the thing for this project.

Tests
1) Let it warm up for a minute or so before running the revs up. One thought I had is that the stator is seeing a large demand from the battery after the e start causing a larger magnetic field.

2)How does it sound and feel . Like normal ?

 

[Jim]

1) Let it warm up for a minute or so before running the revs up. One thought I had is that the stator is seeing a large demand from the battery after the e start causing a larger magnetic field.

Test with and without the alternator powered tomorrow will confirm or deny that.

2)How does it sound and feel . Like normal ?

Very normal. Behaves exactly like the original iggy once the advance curve settles down.

 

[Team Junk]

This is from run #4 . Most advance while "warming up"

 

[5twins]

..... and Jim's added full advance plate does seem to verify what Pamcopete told us years ago, that the left side of the drain notch on the case can be used as a full advance mark .....

 

[Jim]

..... and Jim's added full advance plate does seem to verify what Pamcopete told us years ago, that the left side of the drain notch on the case can be used as a full advance mark .....

Just looked at it closely and, at least on my bike, the notch perfectly defines the 35° to 40° range I made with the pointer.

 

[5twins]

Yes, I was going to mention that the right side of the notch looks pretty close to 35° as well.

 

[TwoManyXS1Bs]

Justa thunk.
Using the trailing pickup?
Reversed, center tap as signal source?

Might be getting a little signal bleeding over from the leading pickup. Would need to scope the trigger signal to see this.

Your retrofit single-pickup could confirm and/or eliminate this...