Bad CDI Symptoms??? ...Or Are They?! ('82 GS450T)

[Showdown]

From what I've found while searching a CDI either works or doesn't.

But can a CDI be bad, still fire both sides and mess up the timing somehow???

*I've checked the signal generator and it tested fine. I have a hot blue spark that jumps from the plug to the head 1/4"+ and shocks you pretty bad.

Is there anything else that could mess up the timing on a 1982 GS450T?
(compression 130lbs+ on both sides, cold)

Basically, it won't start >>> Compression + Fuel + Spark = ??? Bad Timing???

Thank you.

[BassCliff]

Hi,

A few tips:

Igniter/Signal Generator/Coil Test
Igniter Repair/Testing (2MB PDF)
Testing The Ignition System

And don't forget ... New Members, CLICK HERE!!

Are you sure your carbs are properly cleaned? See the guides on my little website.


Thank you for your indulgence,

BassCliff

[Billy Ricks]

Since your bike doesn't have a CDI it would be hard for that to be the problem. You do have an igniter but if you're getting spark you can pretty much rule it out. What all has been done or not done to the bike?

[Showdown]

Ha! I figured CDI = Igniter ???

Can anyone clarify? What's the difference?

The bike is an '82. Completely stock.

[pete]

CDI = Capacitor Discharge Ignition
GS' have transistorised ignition commonly incorrectly referred to as CDI.

CDI uses capacitor charging and discharging to drive the coils where as transistorised ignition uses transistors to drive the coils.

Easy way to confirm timing is set a timing light up while cranking and if the timing is right for both cylinders, your ignitor is good...

[Killer2600]

If you have good spark I would suspect you have a fuel problem. Unless you have a dyna or some similar aftermarket ignition then timing is factory fixed - as said you can use a timing light to check it.

If you suspect you have good fuel because the plugs are wet, you should know a flooding condition will show the same thing and we all know engines won't start when they are flooded. With good spark, plugs shouldn't ever look wet - instead if fuel is good the engine should run.

Spark being out of time so much as to cause a no run/start condition is rare and usually occurs when work has been done to a component that affects ignition timing - like replacing/installing a distributor.

With that last part in mind, one thing to do is check your spark plug wires and make sure the plugs are hooked up to the proper coils, especially if you worked on them since the bike last ran.

[hjacobmiller]

With that last part in mind, one thing to do is check your spark plug wires and make sure the plugs are hooked up to the proper coils, especially if you worked on them since the bike last ran.

Maybe his spark plug leads are reversed on the cylinders and he's getting enough spark just at the wrong time?

[Killer2600]

Maybe his spark plug leads are reversed on the cylinders and he's getting enough spark just at the wrong time?

That's my thinking, it only applies if he pulled the wires/plugs since the bike last ran and now it won't try to start.

If you hook-up the plug to the wrong coil the spark will occur just before BDC (bottom dead center) instead of TDC (top dead center) where it should happen.

[Mekanix]

http://www.thegsresources.com/_forum/showthread.php?t=197071

So far it appears to be the ATU rotor is backwards, confirming the 180' out timing.