83-85 550 and 750 GPZ's ignition problem

I do read infinity on the wires mentioned, so I am gonna look at the pickups more. Would be cool if someone could check theirs on their running bike, but the theory is there. I may try bumping the motor over, until the cam is under a pickup coil and seeing what the reading is then.

Will let ya'll know.

Let's start of by verifying the simple stuff.

The black wire with yellow stripes, measure resistance between the igniter end and the negative terminal on the battery, should be less than 10 ohms.

The red wire, measure voltage (key on) between the igniter end and the negative terminal on the battery, should be 12 volts.

You have a manual for your bike? If so, look in it and see what the resistance of the pick up coils is supposed to be.

Out of curiosity, where the does the black/white out of the IC Igniter go? How does this system control ignition advance if there are no mechanical advance componenets? On most of the IC ignitors without a mechanical advance, they have a vacuum line from the carbs connected to them , like on a Vulcan. The vacuum line has a gizmo that converts the vacuum info to info that can be understood by the igniter to change the advance based on the amount of vacuum it sees.

I traced the black/white wire before, but I forget where it went after the junction block.

None of the GPz igniters use a vacuum signal to the best of my knowledge, they control advance based only on rpm, just like the mechanical advancers do.

Most (if not all) igniters that use a vacuum signal also base off rpm. You really don't want full advance at idle, nor do you want it to drop back to full retard when you are cruising at 5k rpm and crank the throttle wide open to pass someone. Vacuum advance is an addition to rpm based advance, not a replacement for it.

An igniter determines rpm simply by counting the number of spark events in a specified time period.

Post edited by: steell, at: 2007/03/21 12:07

The detailed diagram I have shows different colors for the pickups, but the overall diagram shows red and yellow for one pickup, and black and blue for the other. So I can't say for sure what the colors are for the pickups, and in one diagram it shows the colors get swapped around as it passes through the connector near the igniter.

My manual says take it to the dealer (which is the last thing I'd do) after a few basic checks, but doesn't mention the pickups. If I had to guess the resistance of the pickups, I would say around several hundred ohms. Have you looked under the pickup cover to make sure there are no broken wires etc.?

I see on the diagram, now, that the diode block is a diode-lockout network to disable the ignition under certain conditions. For the most part, we could probably bypass that stuff one way or another. That is the brown/white wire to the igniter (not the black/white, at least on my two diagrams).

EDIT: I wrote this while Steell was already answering, and he already answered it concisely.
The advance is based on RPM which is calculated by the igniter. The mechanical advance is basically an RPM device, and the e-advance igniter just calculates the RPM instead of using a mechanical device.

Classic vacuum advance (on cars) is not designed to advance the ignition based on changes in engine speed. (Actually in the early versions of mechanical vacuum advance, the ignition would retard when you stepped on the gas.) It was an emission and fuel economy device. The car had centrifugal-advance for it's main advance. Most small motors don't need (or at least don't use) vacuum advance. The Vulcan system probably has a similar RPM based electronic-advance system in addition to the vacuum advance sensor. Kaw probably employed some vacuum advance system because of the large volume cyclinders in the v-twin Vulcan.

Post edited by: loudhvx, at: 2007/03/21 12:39

Kaw calls the vacuum advance on a Vulcan a "TPS" or throttle position sensor advance. If I recall, they state they use this type advance as it will more accurately allow the advance to be adjusted accordingly. The reason they do things is often not the reason they say they do things... I dunno... just curious.

I suspect that the pickup coils are the same or close to the same regardless of the igniter type. Here is the method for testing the KZ1000 pickup coils (78-80) models equipped with electronic ignition:

1. Remove the side cover and disconnect the 4-pole pick-up coil connector (this is the connector between the pick-up coils and IC Ignitor)

2. With a multimeter set in Ohms scale at RX100, measure the resistance between the two pairs of leads:
black and blue (No. 1 and 4), and
yellow and red (No. 2 and 3).
the resistance should be between 400-500 Ohms.

3. Set the multimeter in its highest scale and check the resistance between either lead for each pair of cylinders and chassis ground. the reading should be infinite.

4. If the pickup coils fail either of these tests, check the wiring to the coils, and replace the pickup-coils if the wiring is OK.

I would also like to point out that the manual suggests that the IC Igniter is battery powered and will not work right if the battery is dead while the bike runs. I can vouch for this because I have attempted to run a bike with an electronic ignition with a dead battery (trying to charge battery after leaving the key on) and the bike won't much want to run. In other words, verify battery condition and make sure it is charged.

Wow, lots of activity! Since the last post:

Yes, Steele, I have the 12VC and ground on the igniter.

What I do read (or don't, depending on how you look at it) is infinity when measuring out the pickups, and that is on a megaohm scale.

I'll check the wiring at the pickups here soon, but my money is on the pickups. The rest after testing seems to be good to go, but to be sure, I will test that with the 12VDC test in the book.

And good point, wired: the battery is good to go, spinning the starter quite well and reading 12VC after overnight charges. Haven't tested the specific gravity, but honestly don't do that much anyway.

Now last question, loudhvx, is to mak sure: I can use a mechanical advance set of pickups on my system, being that the pickup part numbers cross to the 84-86 550GPZ pickups, without any other mods.

Louie

The 84-86 gpz550's are not mechanical-advance. They use the same system as your bike.

The 81-83 gpz550's were mechanical-advance. You can't swap parts from a mechanical-advance to work with electronic-advance, but you could swap the entire mechanical-advance system into your bike (pickups, advancer, igniter), but that would be a step backward in technology.

Got spark, looks like there was something wrong around the pickup coils. I wiggled/tapped them, and they started working/reading.

Still a yellow spark, with like 11.8VDC on the coils, maybe time for coils now. Shoot, I've changed everything else.

When I get the bodywork back from paint, I'll see if it will fire, but it wouldn't with the gas that has been in the carb for a couple of weeks.

I guess I may eventually call this a "rebuilding year", and not even run it this year. Bummer.

Thanks for the help so far guys, I will try to keep my chin up and ride this once this year.

Hi.
Im new here but in need of your expertese. I have an GPZ 750 from 85, The problem is that it runs unevenly, at low speeds it has problems accelerating but works better at high speed. After about 10 minutes or so it dies....and wont restart until 15 minutes later after cooling down.

I have changed the ignition coils, and checked the plugs and they seem to work fine. Could it be the pickup coil?
Is there an easy way to test this? Other than with a wolt meter.

very informative thread you bumped there from7 years go
#

Tammi wrote: Hi.
Im new here but in need of your expertese. I have an GPZ 750 from 85, The problem is that it runs unevenly, at low speeds it has problems accelerating but works better at high speed.
After about 10 minutes or so it dies....and wont restart until 15 minutes later after cooling down.


are you sure this isn't fuel supply problem? check fuel levels with a clear tube.




I have changed the ignition coils, and checked the plugs and they seem to work fine. Could it be the pickup coil?

change your ht leads and caps 7mm silicon. Unlikely to be the pickup coils


Is there an easy way to test this? Other than with a volt meter
clean up or replace the male coil blade terminals and female connectors under the tank.

Is your tacho working correctly?.

Whats are the blades under the tank? And what is a Tycko? Im from Sweden so my english is not that refined

I did change the ignition coils for two used ones but I suspect that the problem lies elsewhere.