Some Thoughts on The Ignitor

[Guest]

After struggling with my own igniton issues, reading countless threads about broken ignitors and homebrew builds, as well as seeing ridiculous prices on replacements, one thought kept coming to me: Has anyone ever actually opened one up and tried to fix it? I mean, its 1980 technology. I cant be more then a few transistors and a small circuit board or something right? Seems like a few minutes with some fresh components and a soldering iron could give you a nice fresh ignitor for a few bucks. Before I tear into this, I just wanted to see if anyone HAD actually tried this, or if there some secret that if you open it up ittl never go back together and be forever useless? I think my box is actually ok, but its original, and 32 years haven't done it any favors. I have two elec techs at work who have volunteered their time to look at it. Whats everyone's opinion?

[Steve]

I don't remember who it was, but somebody here was working on one.

The '80-'82 models shouldn't be too bad, but they started adding the advance curve in the '83 models, which would make things a bit more ... "interesting".

In reality, it's nothing more than a trigger mechanism that can sense the small signal from the signal generator on the end of the crank, then open a transistor that is capable of handling about 5 amps of current.

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[tom203]

Very first post in this forum, a DIY ignitor. If you've got techies to help, should be no problem.
And what do you mean by "I think my box is actually ok" ? You'll know when it isn't ,just like many others.

[RaiderGT]

Tom are you referring to kokars sticky? Yes I saw that but all the images are expired which dont help and its written for a 550T. Thats actually the post that got me thinking about this. To answer your question: I had spark and bike was running fine, came out the next day and no spark. I was in the process of doing a complete teardown and rebuild anyway so I wasn't concerned with getting a bike running that I was immediately going to take apart. As I started taking the bike apart I noticed more and more horrendus wiring. (all this is detailed in my build thread) I noticed that the pins had fallen out of the connector for the ignitor, so I knew my connection was bad, and not the box itself. However since I am redoing all of the wiring and all of the connectors, I dont want to put an ancient box back in the bike. I figured if it was simple enough to replace the components it would be worth doing and maybe I could help some people in the process. I have noticed several "Ive built a new ignitor box from scratch" posts but that seems overly excessive with the simple circuitry thats in the box. Also it will retain its original footprint.

[JTGS850GL]

No reason to "replace the components" Unless they used electrolytic capacitors inside, which I doubt, none of the internal components will degrade over time. It's possible that moisture damage could occur but that would mean that the conformal coating was compromised and probably not a good candidate for repair anyways. I could see modernizing the design, but the original design (with some exceptions) has proven to be very reliable.

The biggest problem with maintaining a working ignition system on these old bikes is more voltage and connection related. Keeping the voltage in check by maintaining a good charging system (stator and R/R) is key. Many igniters have fallen prey to over/under voltage from a damaged Rectifier/Regulator. There you have opportunities to do some major upgrades. The wiring harness and related connectors are the next biggest culprit for a non working ignition system. Again, here you have many opportunities to upgrade your system.

As for actually repairing a bad igniter, I believe that they are potted which makes things a little harder to perform the repairs. Too many working used igniters out there to make it worth it IMHO.

[tom203]

Send kokar a pm, he's been responsive before.
As Steve said , the ignitor is probably just two FET which conduct coils to ground until their gate is interrupted by signal coils somehow. On my 650 shafty, the ignitor is more module style (rather than box style) but trigger principal is same. I've tested 5 units on my bike and all proved good. As stated, I think these things have problems with over voltage from bad charging- some styles more than others, the 550's the worst.
i keep thinking that member Pete adapted a dyna system to his 450.

[jsandidge]

Be careful not to let the magic smoke escape!

https://www.youtube.com/watch?v=lYzrByJUoGY

[RaiderGT]

According to this guy there are serviceable components inside:

http://www.electro-tech-online.com/threads/igniter-with-two-diodes-in-series.86235

One of the POs had upgraded the charging system at one point. Im not 100% sure but I believe the RR is from a gs500 (it says Suzuki on it but it has an extra wire). Like I said the only reason I bring any of this up is because I am trying to freshen up the entire electrical system while the bike is in 100 pieces. I just didnt feel comfortable throwing a 35yo component back on there without at least looking at it and I didnt want to spend the crazy$$$$ for aftermarket stuff. Also I was curious as to why I hadn't seen anybody attempt this in the past. Some good discussion here.

[tom203]

Good stuff! I liked the info feedback especially this......
"On the SR500 yam they have CDI with a trigger pulse from a small pickup coil, the advance scheme uses a sine wave at RPM frequency, the leading edge of this wave increases in amplitude with rpm increase & relative to the trigger pulse earlier in time."
sure makes me glad that my ignitor is happy!

http://www.electro-tech-online.com/threads/igniter-with-two-diodes-in-series.86235/

[Steve]

I am trying to freshen up the entire electrical system while the bike is in 100 pieces.

...and I didnt want to spend the crazy$$$$ for aftermarket stuff.

Only 100? GET BUSY, it needs to be in a THOUSAND pieces.

Where do you draw the line at "crazy$$$$"? A Polaris regulator is a MUCH better design (series vs shunt) and can be had for about $80, shipped to your door.

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[fmctm1sw]

Very appropriated thread. I think I have a dead igniter. Coils tested good and signal generator tested out as well but there is no spark on 1/4. The manual I have actually has a (blurry black and white) picture of the inside of it. I saw a new one on ebay at about $650 and used ones at $100 plus. That's motivation enough for me to at least open it and look....

[RaiderGT]

Tried opening it, you cant without damaging it. Its all filled solid with resin. Use kokars parts list and build one from scratch.

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[tom203]

Very appropriated thread. I think I have a dead igniter. Coils tested good and signal generator tested out as well but there is no spark on 1/4. The manual I have actually has a (blurry black and white) picture of the inside of it. I saw a new one on ebay at about $650 and used ones at $100 plus. That's motivation enough for me to at least open it and look....

This is a gs650, right? Triple check all connections before you blame ignitor. If you're convinced that it's no good, consider a dyna ignition unit around $110 - much simpler than mucking with electronics.
at only 3000 miles, I'd be real suspicious of connections after a long barn storage. I have two heavily weathered ignitors , but both work fine.

[fmctm1sw]

Tried opening it, you cant without damaging it. Its all filled solid with resin. Use kokars parts list and build one from scratch.

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Crap... just like my pool pump electronics. Thanks for the guidance... I'll look at the connections before I do anything...

[wymple]

In these situations, I mostly find a faulty hot wire to a coil. I will run a temporary wire straight from the battery to test that. Costs nothing to see.