IC igniter

DISCLAIMER: My understanding of KZ electrical systems is simplistic at best. Also, I do not want to derail the thread that triggered this confusion in my little brain.

In a thread started by Maxbou92, some posts have been made suggesting that a weak IC igniter can cause weak spark at the spark plugs. I thought the igniter was little more than a sexy, non-mechanical (integrated circuit) relay that controls the ground leg of the coil wiring. In other words, the igniter does not put out any electrical power of its own, it merely completes the ground or interrupts it. Soooo, the strength of the spark at each plug is controlled by the design and health of each coil and any resistance downstream from there.

Would somebody be willing to enlighten me about this?

If the igniter doesn't "cleanly" break the ground to the coil you would get a weaker discharge on the secondary winding (HT) I suspect to cause a rich mixture it would need to be intermittently miss-firing

TexasKZ wrote:

I do not want to derail the thread that triggered this confusion in my little brain.

 

Now you make me feel guilty. I did just that.
 

ckahleer wrote:

TexasKZ wrote:

I do not want to derail the thread that triggered this confusion in my little brain.


 

Now you make me feel guilty. I did just that.

 

May a thousand sand fleas infest your under shorts.

it sounds possible to blame the IC, but it may be more of an issue of fouled plugs being the culprit.

They could run a hotter plug if they were uniformly rich across their fuel circuits. The hotter plug would keep the plugs clean, but if there was a lean circuit somewhere in there.. pre-ignition may be an issue.

I want to say CDi's have the ability to fire fouled plugs better but that would be a band aid approach to getting to Air/fuel mixture correct.

I would solve for the fueling issue then look at ignition.

Plug chop fun or 4 widebands.

What is also fun is the individual cylinders are interacting with each other through reflected waves in the exhaust. So a rich mixture in one cylinder may affect the fresh charge of another cylinder. 

A cheaper way to 4 widebands is Alan's site.
www.14point7.com
I run 2 at the same time when i suspect problems with fueling.


 

Wookie58 wrote:

If the igniter doesn't "cleanly" break the ground to the coil you would get a weaker discharge on the secondary winding (HT) 

What would cause the break to be messy? ( I suppose my underlying question is how is the thing supposed to work and what could go wrong?)

TexasKZ wrote:

Wookie58 wrote:

If the igniter doesn't "cleanly" break the ground to the coil you would get a weaker discharge on the secondary winding (HT) 

What would cause the break to be messy? ( I suppose my underlying question is how is the thing supposed to work and what could go wrong?)

It's only theoretical (generally these type of devices work or they don't) but an intermittent short due to a failing component on the trigger circuit could mean the coil still had a "partial " ground (think about dirty or corroded points or a bad condenser that doesn't fully "break" the ground) I suspect the scenario is rare but injected mentioned experience of igniter related issues

F64 wrote:

it sounds possible to blame the IC, but it may be more of an issue of fouled plugs being the culprit.

I want to say CDi's have the ability to fire fouled plugs better but that would be a band aid approach to getting to Air/fuel mixture correct.



 

I don't want to be pedantic but for clarity these bikes don't run "CDI" but more like "TCI" - True CDI has a constant ground to the coils and at the appropriate time a capacitor in the ignition module discharges a momentary pulse of between 250 and 600v into the coil primary. These systems generally run very low resistance coils (typically 0.3.-0.5ohms)

Wookie58 wrote:

F64 wrote:

it sounds possible to blame the IC, but it may be more of an issue of fouled plugs being the culprit.

I want to say CDi's have the ability to fire fouled plugs better but that would be a band aid approach to getting to Air/fuel mixture correct.




 

I don't want to be pedantic but for clarity these bikes don't run "CDI" but more like "TCI" - True CDI has a constant ground to the coils and at the appropriate time a capacitor in the ignition module discharges a momentary pulse of between 250 and 600v into the coil primary. These systems generally run very low resistance coils (typically 0.3.-0.5ohms)

Somewhere in a deep, dark, dusty corner of my brain lives a dim memory of Kawasaki using a CDI system on the early H1 triples that proved so problematic that the factory went back to a points system.

Yeah, the CDi would be an aftermarket unit.

I hooked up a12v dc CDi to my Kz440 years ago but i couldn't easily disconnect my mechanical advance so i took the cdi off. The CDi had a built-in advance curve.

It was a dc unit for a scooter. The bike seemed more angry but the ignition could have been overly advanced.


 

Had a 71 H1 triple, cdi ignition, surface gap plugs, and other the over revving the alternator, kills the rotor, never had a problem, using the electronic system from 83/84 in both bikes now, electronic advance, probably not cdi, fuji ignitor bt. works well thx