Sparkplugs

[Irish]

I don't know if this is the correct column but I'll give it a try. Do you get better performance with an "Iridium Plug (sp?) over a regular plug. I know nothing about them. Are they a NEW item? I used to Drag Race in NH & Conn & we occasionally used the "K " series for a slightly hotter plug but I never heard of Iridium! (For instance Champion plug N3k instead of N3). Also does the engine have to be tuned differently? Are Iridium plugs a scooter thing because in NH , I dealt in motorcycles almost strictly.:hmm::thanks:Irish

[bull]

If you listen to the manufacturers, they generate a cleaner spark. While that is true because of the metal molecular structure, it is only applicable to ignition systems that are capable of generating enough electrical power which of course is influenced by many factors you are already aware of. One that you might not know is coil saturation time.

If you look closely at the ignition schematic, the power gen coil in the stator, the CDI, and the ignition coil, you will observe that the discharge capacitor in the CDI first must store enough power in Vac through two crank cycles and that is discharged directly through the ignition coil to ground with literally no coil saturation time- thus you get a very low output.

Even if the coil saturation time were increased to just a millisecond more, then more power which would translate into better starting, running, etc. - With almost any plug or coil!

I just returned from a test ride on a PS model 805, where I had an induction tach (UEI ADL4100) hooked to it. While riding I observed an unsteady rpm with intermittent rpm signal loss. The same test on an otherwise identical scooter running properly had steady rpm and no signal loss.

I am attempting a modification to the CDI and ignition wiring that would allow such an increase. IF I am successful, then most cold weather starting problems as well as others will be a thing of history.

btw.. the scooter with no signal loss runs stronger, and faster even though they are setup identically.

[blueboy5000]

Iridium plugs do theoretically have less resistance, and iridium is stronger and more heat resistant than platinum.

That said, they offer no noticeable difference in performance when used on a gy6 at all.

As to the modded CDI, good luck man. I find your experiment a waste of time, as simply adjusting timing would accomplish the power gains you seek. Also I highly doubt a modded CDI will help with the enrichment and aid in cold starting at all.

[Irish]

Now that I moved from NH to W.Melbourne Florida , I don't worry too much about cold starting!:hehe: Irish

[kz1000st]

Over the decades I have tried them all. Gold Palladium, Iridium, Platinum, Copper Core, regular materials. British, German, Japanese, Chinese. Here's what I'll tell you. There has been no difference in power, fuel mileage, cold or hot starting, throttle response. I had a Chinese Torch plug in the 150 that I changed to an NGK Iridium-no difference.

The only thing I ever noticed is that the more expensive plugs lasted longer. Here's my favorite anecdote. A few years ago I had my Plymouth minivan in for service and I decided to have them do plugs and wires. The Plymouth calls for a plug gap of .050 inch. I saw the standard Mopar plugs they pulled out. They were easily at .100, maybe more. I have no doubt they were the originals or second set and this car had 175,000 miles. It only ran slightly better and gave me 2 more mpg on a trip.

Today's ignition systems are so good in comparison to points and condensers of old. Spark is much higher voltage over a microscopic amount of time. Spark plugs are a very small part of the equation.

[Irish]

Over the decades I have tried them all. Gold Palladium, Iridium, Platinum, Copper Core, regular materials. British, German, Japanese, Chinese. Here's what I'll tell you. There has been no difference in power, fuel mileage, cold or hot starting, throttle response. I had a Chinese Torch plug in the 150 that I changed to an NGK Iridium-no difference.

The only thing I ever noticed is that the more expensive plugs lasted longer. Here's my favorite anecdote. A few years ago I had my Plymouth minivan in for service and I decided to have them do plugs and wires. The Plymouth calls for a plug gap of .050 inch. I saw the standard Mopar plugs they pulled out. They were easily at .100, maybe more. I have no doubt they were the originals or second set and this car had 175,000 miles. It only ran slightly better and gave me 2 more mpg on a trip.

Today's ignition systems are so good in comparison to points and condensers of old. Spark is much higher voltage over a microscopic amount of time. Spark plugs are a very small part of the equation.

If I get everything correctly , it's not worth changing to Iridium Plugs!
Is that correct!:hmm: Irish

[kz1000st]

To me it's just a peace of mind thing. Platinum and Iridium plugs will last longer but they won't magically give you more horsepower or better throttle response. A good engine doesn't care. I kept a set of plugs in one of my motorcycles for over 20,000 miles. I knew it was time for a change when the gas mileage started to drop off.