Fix fried TDI (CDI) for under $20

[Miker]

Feel free to move this thread where it belongs admins.

I bought my '85 FJ1100 in March of last year.  The installed Rick's regulator failed on a ride the following June and took the main fuse, half the TDI, and the 1+4 ignition coil with it.  I have since learned everything about this bike's electrical system the hard way.  Thanks to this forum and one of its members in particular, I relayed the ignition coils and installed the Transpo regulator mod. 

I can't take credit for this idea; I stumbled upon it during research.  I scoured the internet for a way to bypass ebay's used and untested 35 year old TDIs as well as the new, overpriced, poor quality replacements.  I have been running this setup since June 2018 without any issues.  I wanted to wait several months to post this fix to make sure it was viable.  Here is the YouTube vid that deserves all the credit: https://www.youtube.com/watch?v=oq9Gj15fFaE&t=2s

The fix is to wire two Chinese GY6 DC CDIs in place of the single OEM TDI.  Search for the "brand" X-Pro as that is what I am using.  Whatever you buy, you need to verify the size of the units with the seller prior to purchase, which is the only way they can tell the difference between AC and DC CDIs.  Most of the time the seller doesn't even understand the difference and lists AC CDIs as DC.  The DC units are larger than the AC and vary in size.  The AC units are all about 65mm x 38mm x 22mm.

This fix does eliminate the rev limiter (yellow and black wire) and side stand (black and grey wire) relay.  I just tied off those connections. 

I bought all the materials needed on eBay for the cheapest direct from China prices:
2Pcs X-PRO 6-Pin DC-CDI for 150cc 200 cc 250 cc Mopeds Scooters Go Karts Dune Buggy ( I spent about $5 each)
16ga GXL AUTOMOTIVE HIGH TEMP WIRE - 25 FT - WHITE
HCS Ratchet Terminal Wire Crimper Crimping Pliers Tool 3.96-6.3mm 26-16AWG F0P1
2.8mm 2 Pin Car Electrical Wire Connector Male Female Plug+Terminal Kit 10 Sets
10 Sets 4 Pin Car 2.8mm Electrical Wire Connector Male Female Plug+Terminal Kit
50Pcs Uxcell 6.3 mm Female Electrical Spade Crimp Terminals Wiring Connector
50Pcs Uxcell Male Spade Crimp Terminals Wiring Connectors 6.3 mm Width

Per the attached DC CDI pin out diagram, each DC CDI has two ground connections, a DC power connection, a pickup coil connection, and ignition coil connection.  I decided not to cut off the existing terminals and splice the wires so that this fix can be easily reversed.  I converted all 6.3mm spade terminals to 2.8mm via 16ga GXL wire of sufficient length.  I crimped male 6.3mm spade terminals (to connect to the existing wiring) to one end of GXL and 2.8mm female spade terminals to the other end.  Each 2.8mm terminal is to be placed in the appropriate pin hole in a 4 pin or 2 pin connector in order to attach to a CDI unit.  I covered all OEM connections with heat shrink tubing. 

1. Remove the spade terminals from their respective six (loom) and four (pickup coil) pin connector housings.  Search online if you aren't familiar with removing terminals from connectors. 
2. There is a single black ground wire from the pickup coil, which I decided to split off into two wires and connected one to each CDI.  That may not be necessary. 
3. Split off the two black ground wires linked to a single spade terminal from the loom and connect one wire to each CDI. 
4. Split off the two red power wires linked to a single spade terminal from the loom and connect one wire to each CDI. 
5. Connect the orange wire from the pickup coil to the pickup pin on one CDI and do the same with the grey pickup coil wire on the other CDI.
6. Connect the orange wire from the loom to the ignition coil pin on one CDI and do the same with the grey loom wire on the other CDI.

That's it.  I taped the two DC CDIs together and secured them to the frame of the bike in about the same location as the original TDI.  I hope the description and pics are sufficient.  Feel free to respond with any questions or comments. 

[Troyskie]

Great post Mike!

I think there are quite a few who'll benefit from this.

[Miker]

Great post Mike!

I think there are quite a few who'll benefit from this.

Thanks! Another great benefit of this cheap fix is that you can carry a couple extra units around in the tail with your tools.