Is this a knackered TCI? - end of my tether

[melbxs]

I swapped out the TCI with loan TCI and the bike runs as good as ever, BUT.....

voltage readings at the TCI are still all wrong ... so any help would be gratefully received ....

Gray to ground   (book says 12v) .. I get 12v
White/Red          (book says 12v) .. I get 12v
Black/white         (book says 6v) .. I get 1.6v   
Orange               (book says 12v) .. I get 1v   
Red/white           (book says 12v) .. I get 12v


Both coil resistances  are well within range.

Bike runs perfectly at the moment, no cutouts at all.


The voltage at the Orange (left coil) is a concern, yet if I disconnect the 6 pin connector at the TCI and measure the voltage there, it is a true 12v. The voltage only drops when the connector is connected to the TCI.


It could possibly be a bit of earthing in the loom back to the tipover, so I'll try to remove the connector from the block.

Still puzzled by the voltage on the Orange dropping as soon as I  plug in the connector. 

[Jonesy]

Have you checked the pickup coil wires for continuity down at the advance unit? these wires do a lot of bending back and forth and get fatigue brakes in them. you probly already know that but I thought it was woth a mention. cant explain turning the ignition on/off fixing it??

Jonesy.

[melbxs]

Hey melbxs did you find any burnt out tracks in the circuit board?

No signs of any damage on the board. It makes me worry that the ignition advance chip might be dead.

I have re-soldered the pins, will test it tomorrow a.m.

[melbxs]

No, it wasn't me.

Mine is a 4R0 model. A bit rarer than the 2H9 ones. I have dibs on one at the moment. Hopefully mine very soon.

I'm also re-soldering the pins on mine tonight to see if that fixes it.

[Fred]

Hey Brian,

remember when you told me over a beer at St Andrews that I should buy myself a spare TCI, and put it in the parts bin, as they were going up in price and that most were getting to the end of their life?

Well when I saw your post it reminded me of that day and yesterday I got one on the cheap in Ebay. That wasn't you trying to outbid me  in the final 4 seconds was it

[Jonesy]

Hey melbxs did you find any burnt out tracks in the circuit board?

[melbxs]

Ran the meter across the new TCI and all the voltages check out. The bike ran well all the way out to Jeff's place. (35kms)

After balancing the carbs the ride home was even better.

Can't thank Jeff and Dennis enough. Now onto fixing the old TCI. I'll start a new thread as Steptoe suggested.

[steptoe]

if your fix works, like you say document the steps taken,

and so it doesn't get lost to every one, please start it's own thread in w/shop

for fella's like me that can't work that sort of stuff out 

[melbxs]

Well tests with Jeff and following the tests in the back of the manual showed that voltages across the pins were well off.

1.7v where 12v was expected.
1.2v where 6v was expected.

Dennis (dahcar) was kind enough to loan me a spare TCI and the bike runs like a dream. Iam  going to take it for a proper ride today, but things look good. 

I'll detail the steps I take to fix the broken TCI later.

[melbxs]

I have a bunch of tests to do with the meter. Will do them later today.

If I can't determine the problem then I think Dennis (Dahcar) may have a swap TCI I can try. I'll alos keep you in mind Dale if I need to try your TCI - many thanks.

[coe1948]

  Geoff that swap idea works well in theory but in this case i do not have an XS1100 on the road at the moment ,my solo 1100 is in storage and my xs1100 with the sidecar is getting the gearbox rebuilt.I have got quite a lot of XS1100 parts though so i could lend Brian most if not all of the parts that he would like to try out

Regards Dale

[steptoe]

thanx dale,, is there a chance you can take your running bike over to melb,

the way a swap session works is,, you take the box off yours and put on brians, while taking the box off brians and seeing if yours suddenly has the same prob

if no change start swapping other bits, bike for bike till you find something

[coe1948]

   I have probably got a spare one that you could try out to see if yours is faulty i am in Dandenong

  regards Dale

[steptoe]

this is what I'd do,, the day of your 4 member get together, did you get some numbers?

give your closest neighbour a ring for a swap session, the only real sure way before any purchases,,

the other "cheap way", would be to track down a 2h7 box, WITH the spring loaded advance unit,
they'll run just the same, there are a lot more of them than the 4ro boxes,,

just out curiousity, have you checked the regulator/ rectifier, it's a sealed box but might pay to check temp on it when the bike is playing up,, some thing in the back of my mind is bringing it foward,
years ago I had a prob similiar, an auto sparkie found it was suss

[Eveready1100]

My guess would be that the only way to find out would be to swap it over for a known good TCI unit without disturbing anything else and try it and see. I've got a 2H7 unit which wouldn't work properly anyway, but I'm sure someone "local" may have a spare sitting there for you to use. Even if you lift it straight out of their bike, it shouldn't take long to get a result of the test.
This way, you'll know for sure if that's your problem.
If not, I'd be going back to the ignition switch for another dissection and maybe a tweak of the contact plate. Something is interrupting the power feed to the TCI, if it's not the TCI itself.

If I cycle the ignition (turn the key on and off) I get a spark on closing (backfire) and it usually starts straight back up, often dying again moments or minutes later. Flicking the ignition on an off fixes it every time.

This is the sentence that keeps me thinking the switch is the problem.