Curious

[CaptonZap]

Is the red/white wire side of the coil positive or negative?

Positive. The TCI internally completes the circuit to ground.

[barrelguy]

Update

Ok, I had Sparky over to do a look through on this thing. After testing everything possible electrical from the kill switch, the coils, p/u coils, connections and TCI the diagnosis appears to be the TCI where it goes to the p/u coils. Fortunately Andreas the God of Parts has one which I will pick up tomorrow. I will also go back to the original coils for now with the ballast resistor re-installed pending feedback onthe following question:

Has anybody had hotter coils cause a TCI to fry?

Thanks all for the help; I'll let you know the final result with the new TCI.

[DGXSER]

Two things I know about the coils issue;

One, I have installed the Honda VF1000 coils in three XS1100s to date, all of which run happily on them, one I know for certain has over 5,000 miles on the Honda coils.

two, the Honda VF1000 coils are 3 ohm input and 15 kv output, same as the XS11 coils. The only real upgrade to it is replacable plug wires, and availability.

[TopCatGr58]

Hey Barrel Guy,

Where did you get the VF coils from?? Sometimes ebay sellers don't get the right descriptions. Did you check the new coils resistance on the Primary wires before installing them? Some of the newer coils are very low OHM for CDI type ignitions...less than 1 ohm..like 0.7 and that WILL fry your TCI!

I have run high output coils on mine for quite some time also, DynaTek, but like Don said, they need to be 3.0 ohm range.

T.C.

[CaptonZap]

Make sure that the coils you put in are 1.5 ohms primary coil resistance, and leave the ballast resister in the circuit, or get three ohm primary type coils and take the ballast resister out, and wire the red/wht wire directly to the positive terminal of the coils.
Any other value of the primary coil's resistance warrants another post on this board asking for specific directions on how to implement it without harm to the TCI.
(Translation= don't use them)
The output of the spark, "strength", is controlled by turns ratio of the primary and secondary coils, the power (amps) supplied, and the magnetic coupling of those coils, and is beyond your control, other than voltage applied to the primary coil.. If you buy a coil that says you can get 50,000 V out, check and see how many amps in you must supply to get that amount of volts out.
(Translation= there is no free lunch)
The stock coils use about 4 +/- amps, which the TCI is able to handle with no problems. Some coils are more efficient than others, so if you can find some that put out 25,000 V with 4 amps input, great! And let us know how long they last.
(Transalation= anything pressed to extremes fails sooner)

CZ

[barrelguy]

TC - I got the coils from Andreas so the source is completely reliable. 2.9 ohm across primaries on both coils and 15.4 across the secondaries.

DGXSER - I really had no thought that these could do any harm after reading many posts here about happy upgrades. At this point I don't know if the coils caused any TCI issues, perhaps it was on it's way south already?

CZ - what you say makes good sense. I'm thinking I should have stuck with the old adage "If it ain't broke, don't fix it".

Going back to stock setup. On the positive side of things, when I had it out for the ill-fated run that was also the first ride with the new Tkat fork brace - what a huge improvement! Highly recommend these to anybody.

[DGXSER]

Ohh, I by no means say it could not or did not happen that your coils somehow fried your TCI, I am much more comfy with the mechanical things that I can see how they work. I can trace circuits and figure out if power is going where it should, and I can read ohms and amps and such, but I am not knowledgeable enough to know how or why the coils would fry the TCI or what inside it gets "fried" from it.

[TopCatGr58]

Hey again,

Okay, you had good coils, proper ohmage match, so loosing spark now does seem to be point to the TCI failure. Folks have reported such failures, and after taking the covers off....they resweated the solder connections that are on the circuit board...and the TCI then began to work again. The solder joints can go bad from corrosion, vibration, etc. The TCI's are very strong, and aside from trying to run too much current thru them by using too low of resistance type coils, they rarely go bad.

I don't know if Steve made a tech tip from Davinci's previous posts about how to resweat and where to do this to a TCI, but I'll try to find it/one or a link to a thread.

If the TCI is bad, until you replace it, putting the stock coils back in won't do anything for it. IF you are getting a replacement TCI from Andreas, I believe CZ(Caption Zap) is getting into the TCI repair biz....Davinci used to do this, and may still do it, but haven't seen him post here in a while, so I don't know if he's still doing the repairs?

But before you go switching everything back to stock....inspect the TCI by taking the cover off. Don't try to remove the circuit board from the case, it's soldered to the connection pins. Hopefully you will find evidence of corrosion on the solder joints, and will attempt to resweat them and then try the TCI again.

T.C.

[TopCatGr58]

TCI resolder thread

Okay, I found that thread, and have already copied it to our T.U.C. (Tips Under Construction) Forum for near future addition!

http://www.xs11.com/forum/showthread...ght=tci+solder

Scroll to the 3 page to see the full photo spread and such!!! HTH!

T.C.

[barrelguy]

Apparent success

Bit of an update. After rechecking things from start to finish I determined the TCI was ok but the test for pick up coils (GLoweVA's post) only showed +/-720 ohms on one leg. Checked and reinstalled the previous wire p/u coil wire harness and got good readings and fired it up. Ran like crap, likely due to my fiddling with carb stuff I shouldn't have fiddled with. Ended up removing the carbs (a first for me) and did a bench sync (first holes half way covered) and put them back in. Set the idle mixture screws 1.5 turns out and she fires up like nobody's business with no choke at all (also a first). Went out for a short spin, 20 minutes at 100 kph with nary a hiccup. Still runs a little rich (new plugs black and sooty) so I think I will turn the screws in another quarter or even half a turn. Need to do a vacuum sync and check timing and should be good to go.

Any thoughts on running a slightly hotter plug?

In any case thanks very much to all those that chimed in with some very helpful stuff.

[barrelguy]

P.s.

Did I ever figure out the actual, original problem??? Nooooo. So I am going with the fact that it works!