CDI box questions

[club44]

Hey All!

Wondering if someone can help me out with a few questions regarding my XJ1100's cdi box?

My box is done, I had it rebuilt and I think it may have seen the end one more time. I don't want to go that route again!

So, I was wondering if I could use a 78xs1100e tci,pickup coil assembly,engine coils and ballast resister and trick the bike into thinking it is a 78e and run?

Or can a XS1100 box fit the XJ1100?

Finally, I have been told that I can use a different Yamaha box with the pigtail plug to wire onto my 82 and that it should do the trick.

I look forward to any opinions and or comments!!

Cheers!!!!!

[DiverRay]

You can use the '78/'79 box, but MUST change out the COMPLETE advance unit on the crank. The early units used the vacum advance on the crank end, and yours uses a vacum senser under the fuel tank.
I know the timing curve is different, but you should still be able to run well.
Ray

[cokeman]

I was having trouble with the TCI on my XJ as well. From all the info I can gather the 78 box will not work unless you swap the whole ignition out of the older bike. The XJ TCI has the timing curve built right into the box, although it does have a vacuume boost sensor hooked to the carbs. I tried one of the TCI's from New Zealand but it did not work. Too much advance built into it and I was getting fairly severe detonation at 2000- 4000 rpm. It worked fine WOT but I was afraid it would damage the bike. Still trying to get a resolve from them on this, it;s been 4 months now. I finally got the old TCI fixed so the bike is running fine at the moment, turns out it was just a cracked solder joint.

Darrell

[TopCatGr58]

Hey Club44,

As has been said, you CAN use the earlier TCI's, from 78-80 series 2H7, BUT you need to acquire the vacuum and centrifugal advance mechanicals that attach to the crank shaft under the timing cover. Also will need the pickup coils, timing plate, etc. BUT you can use your own 3.0 ohm ignition coils, since you don't use the ballast resistor, it's not needed with this igntion system anyways!!

Randy could/should be able to advise you as to what changes you may need to make to the TCI plugs to work with the early model vs. the XJ's!
T.C.

[club44]

Thanks Guys!!

What do you think is the easiest and most economical way of doing this?

I have someone telling me to use a an older box with a pigtail wired into the harness. Any comments on this?

Cheers!

[TopCatGr58]

Hey Club44,

Randy posted a PINOUT diagram, I think I updated the link in the LINKS section under TCI repair thread, so that you CAN use your Xisting wires, but you may need to modify the plug for the TCI so that the correct wires go to the appropriate terminals, such as the Pickup Coil cluster, and then the other POWER wires, the ones for the ignition coils, the wire for the Emergency Kill switch, etc.!!

You can't just plug in an older box and use it alone. The older boxes don't have the centrifugal or vacuum advance circuitry built into them like your previous XJ TCI did, so you wouldn't have any timing advance!! That's why we stated you NEED to get the other mechanicals for the timing cover shaft end, so that the timing plate can be rotated to change the advance during changes in RPM, and also vacuum variations....light vs. heavy loads!!
T.C.

[club44]

Thanks T.C!

I'll have a look at the diagram and start the parts list.
Cheers!