30 replies to this topic

[MadAd]

Changing the coils for sticks sounds like a bit more of a job that just a straight swap.
I have found an article including circuit diagram to build a multi spark CDI, you could trigger this from the existing TCI.
Now lets see if I can work out how to attach the file!!
Nope upload failed.
If you are interested in reading then you can find it at http://www.molla.org...ticle-hires.pdf
Hope this provides some entertainment!!

[JBX]

After doing some search work on the ignition system, it appears there is no more CDI on Yamaha's bikes since a long time (before 2000), even on high-performance bike - R1 / R6 - with high rpm engines !

It looks like modern digital TCI have reached a good-enough performance level compared to CDI, without the higher cost of built...

The last CDI system found was on the R7, I also found some 2-strokes with it (350RDLC).
Coils used on these CDI had very low primary resistance : 0.16 to 0.30 ohms.
These coils are of course non-compatible with TCI system.

All Yamaha's models now have digital TCI system and some of them have stick coils : R1, R6, XTZ1200, etc.
The TCI stick coils have various primary resistance : 0.85~1.20 ohms (R1), 1.2~1.6 ohms (XTZ1200).

I really don't know if these coils could go on the TDM, and I'm not willing to dare to experiment that on my own bike !

[MadAd]

That is an interesting discovery!!
I have been looking at building an auxiliary driver circuit to pop on the output of the TCI that can handle the lower resistance modern stick coils.
It's not finished yet though!!
And it's going to be a long time before I can test it!!
Not ready to post it up yet as have not finalised the components yet!!

[Margus]

That is an interesting discovery!!
I have been looking at building an auxiliary driver circuit to pop on the output of the TCI that can handle the lower resistance modern stick coils.
It's not finished yet though!!
And it's going to be a long time before I can test it!!
Not ready to post it up yet as have not finalised the components yet!!

Keep us informed! And pic's please!!!

[TinTin]

I assume someone has checked they will fit in the hole for the plug cap?
I have them on both the FZ and ER6 and they look a tight fit to form a seal found the top to keep the wet out.

[Studley Ramrod]

Just been reading some info off the Banditalley site http://forums.bandit...?topic=12808.15

They seem to think that, with a wasted spark system, wiring the stick coils in series doubles the resistance eg. 2 x 1.6ohm stick coils = 3.2ohms resistance.

Soooooooooo, if that was the case then a couple of 2.2ohm stick coils wired in series should work.

Edited by Studley Ramrod, 20 April 2012 - 01:36 pm.

[JBX]

I'm not sure that would be great with a 270° crankshafl engine !

[Studley Ramrod]

Me neither JB, I 'aint gorra dotty blue !

[Jankers]

If you do find some coils that will work then a word of caution; on the ER6 there have been a number of instances where the coil/plug refuses to come out.
It seems that water gets into the body or the unit and rusts the 'liner', which expands enough to make removal very difficult, sometimes impossible without breaking the coil part. There is little clearance between the unit body and surrounding engine casing so even a good unit can be fiddly to remove.
Not tried it myself bit several reports on the subject.

Something to keep an eye on.

J.

[Catteeclan]

If you do find some coils that will work then a word of caution; on the ER6 there have been a number of instances where the coil/plug refuses to come out.
It seems that water gets into the body or the unit and rusts the 'liner', which expands enough to make removal very difficult, sometimes impossible without breaking the coil part. There is little clearance between the unit body and surrounding engine casing so even a good unit can be fiddly to remove.
Not tried it myself bit several reports on the subject.

Something to keep an eye on.

J.

I've seen this on a zx250r. The bike was missfiring so I pulled the coils out to find them falling apart. There was a thin plastic outer covering a thin tube of metal which had expanded with rust over the tube of the coil. They were not to much trouble pulling out in this case but I could see they would be with more time.
Wouldn't mind betting the prob is down to crap components as well as condensation.

[MadAd]

Been looking some more at the secondary driver circuit and have decided to scrap the idea after working out that just the logic required to change the TCI output to drive a bigger IGBT would delay the spark by more that 2 degrees at the red line.

I have found a spare TCI in the garage that I'm going to pop the board out of to see what is in there. There will be picks when the butchering is over!!