Looking for ideas on upgrading Ignition

kshansen

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Was wondering if anyone has done some upgrades to the ignition on a points ignition XS400. Mine is a 1978 XS400. I;m thinking it would help it start a little better. I know my 1982 XS650 with electronic ignition will start with two or three kicks even when parked for 10 hours at near 0ºf temps
 
I have two xs400's one with points and one with the factor tci ignition and they both start just as easy. You can change over to a 80-82 sohc xs400 tci setup with your 78. You will need the coils, pickup and tci box as well as some wiring changes to get it to work.
 
Hiya, will you need the coils? The points and TCI should both use inductive coil types? I thought it was only CDI ignition systems that needed different coils because of the capacitor discharge voltage? Maybe I'm wrong as don't know everything ;) do they have slightly different resistance or something?
:)
 
I used the same coils for the oints and pirana ignition i used (till it failed)

I did post plans to build a TCI on this forum if you care to do a search.

BTW

capacitor discharge ignitions were last used on kawasaki 2 strokes in the 70's.

TCI and digital ignitions are now common place. ;)
 
The TCI bikes 80-82 used a 3ohm coil where the 77-79 points bikes have a 4ohm coil. Not to say it won't run with a 4ohm but you don't want to burn something up:)
 
Hiya Drewpy, maybe its a terminology error I've made, people seem to call modern bike ignition control units CDI's so I presumed they actually were cdi's which would fit in with modern high rpm engines?

Guess they are all actually digital transistor ignitions?

Thanks for the info Chris, I did wonder what the ohm'age was, its this primary or secondary coil resistance?
 
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The TCI bikes 80-82 used a 3ohm coil where the 77-79 points bikes have a 4ohm coil. Not to say it won't run with a 4ohm but you don't want to burn something up:)
Chris,
Sorry to resurrect an old post, but I’m building a bike using an 81 XS400S motor with a TCI unit. The engine came with the TCI unit, the pickup is still in place, but no other electics. While I’m working on getting the electrics dialed I’ve been digging through some old components and found a nice set of 3 ohm Dynatek coils that I had bought for a Shovelhead build. Any reason why these won’t work?

Thanks to you and any others that may chime in here.
 
Make sure the primary and secondary resistance are the same as what the stock coils have and you should be fine. The only thing would to watch for is those coils burning out. I guess they can be very touchy if the bike gets turned on or try to run without them being hooked up to a plug. High voltage!! If they work post your results.
 
Thanks Chris. I’ll have to do some research and testing to figure out the secondary resistance. I believe the TCI bikes call for 8.6k Ohms. Any experience with acceptable range? I don’t think the service manual calls out a tolerance. I suppose +/-10% should keep me in a safe window.

I’ve done a few Harley’s with Dyna coils and one with their ignition system too. No doubt they pump the voltage. I’ve had good luck running NGK Iridium plugs with these. That said, I’m eyeing a stock harness and coils on fleaBay right now. If they work, that’ll be a safer route for sure.

I’ll post some build pics as I progress.
 
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