Poll - would a new TCI/Igniter for the XS11 be worth it?

[mainlylinux]

In a previous thread Steve had mentioned using a Hall effect device to replace the pickup coil in the ignition system (because it would be a nicer signal to a new TCI/Igniter system.

If you were going to use this new Igniter would you be willing to change pull out your old pickup coils and install a hall effect sensor?

Dan

[DiverRay]

I have spare parts for stock, but I'm looking to upgrade for the "winter project". My problem is like most of us, I don't have a lot of disposable income.
If you can put together something that works, and keep the price under about $100, I'll probably go that way. If I can switch to different coils with a bigger kick, so much the better.
Ray

[randy]

Poll - would a new TCI/Igniter for the XS11 be worth it?

Today it's worth about $50.

Tomorrow? When the spare supply dries up? Priceless!

[Pat Kelly]

$50 - $100, is it worth it? Would we notice anything different with our bikes?
$85 for a Tkat forkbrace and you immediately can tell where your money went.
Progressive shocks and forksprings, can usually tell a difference.
I went from stock coils to Dyna coils. My diagnosis led me to the need for new coils and there weren't any on Ebay at that time. I had thought of aftermarket coils so there was a good excuse. Cost me $170 and I feel it was worth it though there seemed to be negligable improvement but I did notice an improvement. As an aside to that, the problem was with the TCI box .
We now have an alternative voltage regulator that provides voltage at lower RPM. We know it's there and what's happening but does the bike run better?
Switching to fuel injection. I don't recall any conclusive report on this.
Switching to a different ignition system. Is there any reason to? Would it be more reliable? Last longer? Be easier to get replacement parts?
Are we reinventing the wheel or improving it?
This reminds me of a thread from a year or so ago, to restore these bikes like original or to upgrade trying to keep-up with the new bikes. Like I replied in that post, I see and endorse both sides. My solution was to have 2 XS11's. My E is the one I've done upgrades to. My midnight special I'm trying to keep original. I think of doing this or that to it and I have to remind myself of my goal of keeping it original (for riding comfort I have changed handlebars and added a small fairing. I'm hanging on to the original bars 'just in case').

I would consider the new TCI/igniter on the E just for the hell of it and would buy it for the LG if that was all that was available to keep it running.

[Pat Kelly]

Thank you for making this poll with multiple votes!!

[mainlylinux]

any benefit

Well, for me there would be a few of benefits:

1 - no need to hunt down a used TCI if mine goes bad

2 - revlimiter built into the new TCI design

3 - the ability to change the timing curve of the engine

4 - much hotter spark for easier starts

5 - ease of coil and plug wire replacement

On number 4 I know that I shouldn't need hotter sparks, if my carbs and jetting (or fuel injection) are all dialed in. But even when my XS had carbs it would miss on startup a little bit until she ran for a few minutes.

[Pat Kelly]

That all sound great.
I wasn't trying to put-down your efforts. Just playing "devil advocate"

[randy]

Dan,

Your project sounds very ambitious and I'm interested to see what you come up with.

Rev limiting and timing curve adjustments were never included in my plans. I was going for a plain vanilla TCI replacement. Should be enough to get you going, though. I'll post it later.

[mainlylinux]

I knew from the beginning that there would need to be a timing curve for this to be useful for a bike without the advancer like the xj's. Revlimiting doesn't seem like it would be to hard to do.

I was planning on using a small inexpensive microcontroller, a PIC, to do the calculations and trigger the coils.

Dan

[mainlylinux]

That said, I've never programmed a microcontroller.

How hard can it be :-)

Seriously, there's alot on the internet to help with the PIC.

Dan

[TopCatGr58]

Hey Dan,

IT's not just the XJ's that need the timing curve, but the 81XS also needs one, cause it doesn't have a centrifugal advance, only the vacuum /retard unit, the advance is in the TCI, that's why Randy can't replicate it or replace it's PIC! The 78-80's that use both Cent. and vacuum will be the easiest, unless you plan on making only 1 style, and those that are going to install/ upgrade their TCI will then either need to Cap off the vacuum piston, and/or also remove or FREEZE the centrifugal advance parts, so then all they would need to do is ADD/change the Pickup coils, vs. being able to use the OEM's depending on your design!?

Thankfully, I've got a spare TCI for my 81, but if I didn't have it, then I know I'd be looking closely at your project!!
T.C.

[mainlylinux]

this should work for the '81 as well.

I haven't looked at how hard it would be to freeze the advancer parts. Could it be as easy as drilling a hole thru the plate with the springs and putting in a tiny bolt to prevent advancing? that type of modification would be reversible.

what type of hardware is in the '81 and the XJ's TCI that control the advance now?

knowing the advance rates and rpm's for the pre 81, 81, and xj's will be helpful as well. Does anybody have those plotted out?

Dan

[mainlylinux]

I'll be looking at how megasquirt 'n spark handles ignition events and try to learn a thing or two.

But I pretty much imagine it might go like this:

1 calculate rpm

2 look up or calculate advance at that rpm

3 based on those two factors, fire the next cylinder x milliseconds after the previous cylinder's pickup coil event.

4 number of milliseconds to fire before reluctor passes the pickup coil threshold is related to the number of crank degree per second that the crank is moving at. Example being if at 5000 rpms the crank moves 20 degrees every 10 milliseconds, and i want to fire @ 20 degrees advanced, I will fire the coil 160 degrees after the previous coil's reluctor event, which would be ~ 80 milliseconds.

I'll try to draw a diagram.



Dan

[mainlylinux]

Here's a basic block diagram:

[xs650mike]

Originally posted by Pat Kelly
I went from stock coils to Dyna coils. My diagnosis led me to the need for new coils and there weren't any on Ebay at that time. I had thought of aftermarket coils so there was a good excuse. Cost me $170 and I feel it was worth it though there seemed to be negligable improvement but I did notice an improvement.

Don't think I'll ever spend $170 on Dyna coils or Accel coils when I could get coils from Mikes XS http://www.mikesxs.com/mikesxs-elect...ategory_id=2.1 part #17-6803 for $28 apiece or $56 the set...especially since I ohmetered the expensive Accel coil I bought for my XS650 and found it to be the exact same spec as a stock Yamaha coil.