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Stainless tig 1 S just trying to do some troubleshooting on my zrt 800 from hell, and i really dont know what the job of the CDI is. Thanks! #1 · Mar 9, 2010 just trying to do some troubleshooting on my zrt 800 from hell, and i really dont know what the job of the CDI is. Thanks! Sort by Oldest first Oldest first Newest first Most reactions #2 · Mar 9, 2010 In a nut shell, the trigger on top of the flywheel housing tells the CDI when to start the spark. That's why you put an advanced key in..it advances the flywheel in the clockwise position which in turn "triggers" the pulser/trigger coil sooner than a stock timing key does. The CDI accepts the voltage coming from the stator and stored it in a capacitor. It also has a diode in the CDI which converets the AC voltage it receives to DC voltage which goes out to the seccondary coils (coils with the plug wires on them). SO the CDI accepts the AC voltage, it releases the stepped up DC voltage when the trigger tells it to start the spark and it controls the duration of the spark. Of course at higher RPMS you're talking about things working in fractions of a second. Basically the CDI acts like the old points and condensor...it stores energy, increases it by using the capacitor, releases the energy and controls how long it outputs the energy. Basically the CDI controls your timing at varying RPMS. Some CDI's give you more advanced timing at different RPMS. As fas as testing one....other than reading voltage output coming from the CDI when you pull it over (It reads in DC voltage and you can't measure it with a regualr multimeter because it pulses or releases the voltage to the coils and stops so fast) I don't know of a full proof way other than testing a known good one or bad one on a running or nonrunning sled. You really can't ohm them out. #3 · Mar 9, 2010 are the 3D CDI boxes tht cat had lets say on the later triples "BETTER" performance wise versus the older CDI ones.. i can see where they can put a bunch of timing up top in the rpm range but back it off down low and even lower for easier starting.. #4 · Mar 9, 2010 <div class='quotetop'>QUOTE (cweinzatl35 @ Mar 9 2010, 08:52 AM) <{POST_SNAPBACK}></div>

are the 3D CDI boxes tht cat had lets say on the later triples "BETTER" performance wise versus the older CDI ones.. i can see where they can put a bunch of timing up top in the rpm range but back it off down low and even lower for easier starting..[/b] Click to expand...

Better?...?..ehhh...well....kind of...ummm.. depends.... I think it was the 2000 CDI that had 9 degrees of total timing at WOT. Most other years have in the 12 degree area. Some CDI boxes have more advanced timing faster in the RPM range...so it kind of depends on what youu want to do with your sled...trail ride, race ect...I have a complete 93 ignition with one of my own stator rewinds in it on a 2000 chassis. I wanted the more aggressive 93 CDI and to get rid of the TPS. I also have my TSS unplugged. The only thing that works on mine is the key. It also depend on what kind of "tune" your sled is in....does it have pipes, reeds, big bore ect...you can see a little more bang for your buck with different CDI's but some cdi's you can add a key and be just as good. For each application you have to field test with timers or dyno it to really know for sure. #5 · Mar 9, 2010 <div class='quotetop'>QUOTE (Blaine @ Mar 9 2010, 06:51 AM) <{POST_SNAPBACK}></div>

In a nut shell, the trigger on top of the flywheel housing tells the CDI when to start the spark. That's why you put an advanced key in..it advances the flywheel in the clockwise position which in turn "triggers" the pulser/trigger coil sooner than a stock timing key does. The CDI accepts the voltage coming from the stator and stored it in a capacitor. It also has a diode in the CDI which converets the AC voltage it receives to DC voltage which goes out to the seccondary coils (coils with the plug wires on them). SO the CDI accepts the AC voltage, it releases the stepped up DC voltage when the trigger tells it to start the spark and it controls the duration of the spark. Of course at higher RPMS you're talking about things working in fractions of a second. Basically the CDI acts like the old points and condensor...it stores energy, increases it by using the capacitor, releases the energy and controls how long it outputs the energy. Basically the CDI controls your timing at varying RPMS. Some CDI's give you more advanced timing at different RPMS. As fas as testing one....other than reading voltage output coming from the CDI when you pull it over (It reads in DC voltage and you can't measure it with a regualr multimeter because it pulses or releases the voltage to the coils and stops so fast) I don't know of a full proof way other than testing a known good one or bad one on a running or nonrunning sled. You really can't ohm them out.[/b] Click to expand...

You are good, informative post. - Thanks #6 · Mar 9, 2010 I agree! thank you very much for the information. Im starting to understand more about all those little wires under the hood. Insert Quotes Post Reply

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