• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

CDI vs Electronic Ignition

  • Thread starter Thread starter dtkid
  • Start date Start date
D

dtkid

Guest
Question for general knowledge:

What is the difference between a CDI-ignition and an Electronic ignition. I actually thought they were the same.
 
totally different systems
CDI= capacitor discharge ignition
cdi uses a magneto coil to generate power which is Burt up in the ignition coil/capacitor and is triggered by points or a simple electronic trigger.
it does not require a battery.

cdi is commonly found on dirt bikes and small displacement street bikes, primarily single cylinder bikes.
Honda did use cdi on the cb/cm 400-450 twins
all GStwins from the 250 to the 500 have used battery powered ignitions.

most street bikes larger that 250cc have what is called battery powered ignition, they take power from a battery and it generates high voltage in the secondary windings in the coil, in this case, the electronic ignition controls the ground side of the coil/s
the system used on GS's uses small coils and a trigger wheel to time the ignition as the magnet in the trigger wheel passes the pick up coils a small electrical current is generated in the coils, the ignition control box uses this current (signal) to determine when to trigger the coils.
starting in 82 Suzuki started to use a fully electronic system that also electronically controlled the ignition advance by detecting the engine speed via the signal from the pick up coils.
prior to 82 (and on some 82 models) ignition advance was controlled by the same mechanical advance system the points system used.

on battery powered ignitions, (points and electronic) a battery is required.
 
Last edited:
Focus,

thanks for the explanation. I've always wondered the same.

Follow up question: in priot-to-82 models which have battery powered ignition, do you still need to adjust/replace the points as part of a tune up? From your explanation it sounds like the points are used only for ignition advance. Does this mean they are maintenance free (like the fully electronic post-82 models).
 
Points pit and wear down with use. They should be replaced. I replaced mine about every 7-10K miles. Its a good idea to replace condensors at the same time also.

Earl

DimitriT said:
Focus,

thanks for the explanation. I've always wondered the same.

Follow up question: in priot-to-82 models which have battery powered ignition, do you still need to adjust/replace the points as part of a tune up? From your explanation it sounds like the points are used only for ignition advance. Does this mean they are maintenance free (like the fully electronic post-82 models).
Click to expand...
 
Suzuki used points up to 1979, they switched over to electronic ignition for 1980.
 
dtkid said:
Question for general knowledge:

What is the difference between a CDI-ignition and an Electronic ignition. I actually thought they were the same.
Click to expand...

There's a excellent guide at http://www.jetav8r.com/Vision/Ignition/CDI.html

Crude summary:

CDI uses energy stored in a charged capacitor and the coil as a step-up transformer to produce spark.

Points & coil (Kettering) and solid state equivalents use energy stored in the coil when the current flowing in the primary winding is suddenly stopped.

Electronic commonly means any ignition using solid state switching. The first system I put on my car 30 years ago used the points to trigger a transistor switch on the coil primary. Later systems replaced the points with a Hall Effect device or other non-mechanical trigger. Modern electronic ignitions are integrated into the engine management system and do black magic under all engine conditions compared with earlier types.
 
Last edited:
My old H2 had CDI and put out some impressive voltage. While pulling a plug lead with insulate pliers the current still got to me, so bad that I couldn't let go of the pliers or the throttle. What was it about electronic ignition that made it win out over CDI??
 
Mr. Jiggles said:
My old H2 had CDI and put out some impressive voltage. While pulling a plug lead with insulate pliers the current still got to me, so bad that I couldn't let go of the pliers or the throttle. What was it about electronic ignition that made it win out over CDI??
Click to expand...

:-) indeed. CDI makes a short duration spark and high open circuit voltage. Great for firing wildly variable mixtures found in 2 strokes. They certainly try hard to find other paths to earth when a plug lead is lifted.

With 4 strokes, particularly with the accurate metering of fuel injection, it's better to have a longer duration more controlled spark achievable with other types of electronic ignition.
 
Last edited:
You must log in or register to reply here.
Back
Top