I think I have a bad IC Box

I think I have a bad IC-igniter, my ignition starts to break up at around 7 grand under full throttle. Any help would help me out.
Mark

loudhvx wrote:

Mark Wing wrote: I think I have a bad IC-igniter, my ignition starts to break up at around 7 grand under full throttle. Any help would help me out.
Mark

If it used to rev fully at wot, and now doesn't, and assuming it's electrical...

In addition to the igniter, it could be:
1)spark plugs gapped too far (eroded with age)
2)coils failing gradually
3)plug wires and/or caps
4)voltage to the coil is dropping due to connectors or switch losses.

These problems will be worse if 3-ohm coils are used instead of stock 2.3 ohm coils.


1 is easy to check.
4 can be tested by running a wire from the battery directly to the positive side of the coils.
3 just requires physical inspection for age and condition. May be simpler to just replace. You can get wires cheap at auto parts stores. Autoone will sell single wires tat can be cut in half to make 2.
2 is harder to test. You can ohm them out to get an idea if they are bad, but cannt confirm they are good.

I use a test circuit to check coils, as that seems to be the only way to know for sure:
www.kzrider.com/forum/21-tools/561376-true-coil-tester

We should probably start a new thread so as not to jack this one... plus, I may have some paint questions for you.

I've got new plugs, new wires, I've tried different sets of coils and tried different pick-ups, The only thing the same is the IC box. I didn't understand the graphs you listed to check things out.

I had a Run-On-Off Switch, Switch housing (RH) have a bad connection and at 5000rpm's the bike would break-up. By chance after checking most of the things you have listed, I was riding the bike looking for the issue and thumbed the switch inadvertently at speed while the bike was breaking-up and the bike took off... Problem solved. Check it.

Mark, I have a good IC ignitor box from an 82 GPz750 I can give you.

Mark Wing wrote: I've got new plugs, new wires, I've tried different sets of coils and tried different pick-ups, The only thing the same is the IC box. I didn't understand the graphs you listed to check things out.

I would also do a quick voltage check to the coils.

Set the meter to DC volts, and connect the red probe to the yellow or red wire on the coils, and the black probe to the battery's negative post. Then rev it and see what the voltage is.

Paul that would be great, do you need my address again.

loudhvx I forgot to add that I've done the coil mod with a GM relay.

Kraz1 my kill switch has been bypassed for a few years now.

Thanks for the reply guys.

You could have the relay losing contact do to vibration. Ditch the relay and fix the reason for the low voltage. Also if you have low voltage to your coils, whats the drop to the ignitor. best to get it right and ditch the relay/ bandaid.
Also you should take your meter and set it to AC Volts, put the leads across the battery and measure for AC Voltage in the system. If more than .3 ACV unplug the R/R and retest. You would have a leaking Diode in the R/R, which can cause problems with the ignitor.

I'm watching this very closely as I have the exact same problem. I had to do the relay coil power trick as I was getting 10.something volts at the coils. I "upgraded" my bike to an electric ignition thanks to ebay. Some really interesting suggestions here.

Thanks for the tip Motor Head, I'll check that out. I did the coil mod after the problem started, I was getting over 12 volts to the coils before but I did the mod to make sure I was getting good voltage to the coils.

Mark

On a side note I saw Motor Head at a roller rink in Fullerton Cal. many years ago, when the opening band was playing Lemmy was playing pinball in the lobby.

I have your address Mark I am in Sol Cal this week but I can ship it you on Monday.

If you get a good used one, it will be your quickest easiest test.
But don't forget the ground equation. Make sure you don't have a weak ground to the ignitor also.
In "File Base" there should be a wiring diagram for your bike. I believe the Black/ Yellow wire will have a splice in the harness for the ignitor. One test would be to add another ground at the ignitor to test if it is weak. Or you can Ohm it, check for voltage drop, Milli-volts, etc.