proper spark plugs

[scotty524]

Hi there,
i was going to change my plugs this fall in my 99 kat 750 and although it calls for NGK cr9ek's the bike has plain ol' cr9e's in it. cr9e's are about $5 ea and cr9ek's are about $18 ea. is it ok to run single electrode plugs in my bike or should i get the dual electrode OEM plugs. the suggested iridium plugs are single electrode so why does it call for dual electrode for OEM? thanks.

[DClark]

Hi there,
i was going to change my plugs this fall in my 99 kat 750 and although it calls for NGK cr9ek's the bike has plain ol' cr9e's in it. cr9e's are about $5 ea and cr9ek's are about $18 ea. is it ok to run single electrode plugs in my bike or should i get the dual electrode OEM plugs. the suggested iridium plugs are single electrode so why does it call for dual electrode for OEM? thanks.

Dual electrode plugs are intended to give longer life. A racer told me that a dual plug can have the effect of slightly advancing the ignition as the plug with the least resistance will fire. They'll never fire at the same time, forget what the split fire ads looked like.NGK recomends the dual plugs for better life, but I think I read somewhere that thy make no other claims (better power, mog, etc) for them
For plugs, I see two paths to go- cheap and pricey. For cheap, look for an autolite replacement, autolites for bikes can be found for as cheap as a buck a plug during sales and honest to gawd, I never saw a performance between them and the more $$ ngk. In fact, Dale Walker, the Bandit God runs them in his bike. I won't ever pay $5 again for a regular copper core plug, especially when you get four of another brand for that price.
Pricey? I have ND Iridiums. Again, I won't make a claim that the bike will have more power with them than a dollar autolite, but they do have a wide operating range and the bike sure starts up well with them when it is freezing.
I did the coil mod to get more juice to them and the next time I check my valves, I'll widen the gap on them to see if that improves things.

[niqbales]

Dual electrode plugs are intended to give longer life. A racer told me that a dual plug can have the effect of slightly advancing the ignition as the plug with the least resistance will fire. They'll never fire at the same time, forget what the split fire ads looked like.NGK recomends the dual plugs for better life, but I think I read somewhere that thy make no other claims (better power, mog, etc) for them
For plugs, I see two paths to go- cheap and pricey. For cheap, look for an autolite replacement, autolites for bikes can be found for as cheap as a buck a plug during sales and honest to gawd, I never saw a performance between them and the more $$ ngk. In fact, Dale Walker, the Bandit God runs them in his bike. I won't ever pay $5 again for a regular copper core plug, especially when you get four of another brand for that price.
Pricey? I have ND Iridiums. Again, I won't make a claim that the bike will have more power with them than a dollar autolite, but they do have a wide operating range and the bike sure starts up well with them when it is freezing.
I did the coil mod to get more juice to them and the next time I check my valves, I'll widen the gap on them to see if that improves things.

You said it just as I would. I don't see how it's possible to get more power from a different plug... A bigger spark doesn't make a bigger explosion. Correct me if I'm wrong...

More money should equate to:
Longer life
Possible higher reliability

You can make cheap ones last longer if you're willing to take em out and shave em down... I don't like creating extra maintenance so I usually get nicer than the cheapest.

[DClark]

More money should equate to:
Longer life
Possible higher reliability

.

The iridiums will last long, long time. True story- (I posted this before, but will again)I took my '06 GTO with 18K miles for a dynotune. Stock plugs were NGK Iridiums. The owner said that new copper plugs should give a little more power (whatever), so they installed them. Air pressure, air temp, was all same as before.Did three pulls and each one showed a loss of about 2 hp. Small amount? Yes. Small enough to say insignificant? Yes. However, it was interesting to note that it was less than the iridiums with 18k miles on them. Cyber poet wrote something about them if you want to search. Because iridium is a great conductor and is hard, the electrode can be real narrow, like a racing plug,so it gives a slightly bigger spark, something that might be more noticeable on a bike with a weak *** ignition like mine. Then again, you'd probably get a much better spark by just getting some relays for the coils.
So, spend the big bucks for iridiums and you getlong life and better cold running. Cheap out and get the autolites and you get better chance of cold weather fouling, good performance in most other situations and you'll have enough $ saved to get a couple of six packs of some really good microbrewed IPA- you really can't lose either way!

[niqbales]

Wow 2hp is still a power gain. Maybe it fires more precise? I don't know how a bigger spark equates to more power unless a bigger spark ignites the a/f mix faster... That's good info tho. I use standard ngk, I'll look into an upgrade when it's time to switch...

[loudnlow7484]

The dual-strap plugs that come factory in the pre750's give more piston to plug clearance. The ground straps sit to the side of the electrode instead of over the top of it. I've run normal plugs without issue, but I have the correct plugs in this one because it makes me feel better.

[DClark]

Wow 2hp is still a power gain. Maybe it fires more precise? I don't know how a bigger spark equates to more power unless a bigger spark ignites the a/f mix faster... That's good info tho. I use standard ngk, I'll look into an upgrade when it's time to switch...

Not really much of a gain when you dyno at 361hp. I don't think you would notice it. If you were to take the same percentage gain and apply it to my kat 1100, it would be a .7hp gain, which is next to nothing.
You could say that the a new copper plug and a old iridium plugs dyno the same.
You could also probably say that there is a noticeable drop in power between iridium plugs with 18k miles and copper plugs with 18k miles.
Like I said, better life and cold running, go with iridium, but if you want more power, look elsewhere. Actually, I think for better performance and for less $, rather than buy iridiums, buy some autolites and rig up some relays for your coils. The bike runs smoother with them, but the proof in the pudding is being able to fire the bike up in 50 degree weather with NO choke! Yeah, great spark!
I think the cost of a relay and wire for my bike was under $10 and it took about one hour to do.

[4banger]

Is there a write-up on this coil mod?

[DClark]

Is there a write-up on this coil mod?

http://katriders.com/vb/showthread.php?t=110656

[niqbales]

Not really much of a gain when you dyno at 361hp. I don't think you would notice it. If you were to take the same percentage gain and apply it to my kat 1100, it would be a .7hp gain, which is next to nothing.
You could say that the a new copper plug and a old iridium plugs dyno the same.
You could also probably say that there is a noticeable drop in power between iridium plugs with 18k miles and copper plugs with 18k miles.
Like I said, better life and cold running, go with iridium, but if you want more power, look elsewhere. Actually, I think for better performance and for less $, rather than buy iridiums, buy some autolites and rig up some relays for your coils. The bike runs smoother with them, but the proof in the pudding is being able to fire the bike up in 50 degree weather with NO choke! Yeah, great spark!
I think the cost of a relay and wire for my bike was under $10 and it took about one hour to do.

I just couldn't imagine any at all but I guess if the spark was insufficient to begin with it would make at least a minor difference in power. Like you said it may not be noticeable difference. I definitely need to do the coil relay mod tho...

[scotty524]

thanks for the replies guys, so in other words, it's really up to me what i put in. CR9E's, CR9EK's or CR9EiX's will all do the job. i just wonder why they don't say CR9E's even CAN be used and they say the iridium's can when they are both single electrode plugs. well what if i say that i live in ottawa ontario canada and run my bike from end of march into november (as hot as 40 degrees celcius and as cold as 8-10), my shortest rides are about an hour long, and the bike really hasn't had any snap to it until fully warmed up.

[DClark]

I just couldn't imagine any at all but I guess if the spark was insufficient to begin with it would make at least a minor difference in power. Like you said it may not be noticeable difference. I definitely need to do the coil relay mod tho...

I think any improvement in spark is good because these bikes have crappy, weak ignitions. Some proof of this can be found in the bike specs. These bikes have relatively low compression motors and despite, that, the plugs are spec'd for a real small gap. I guess a larger gap would result in missing. How much voltage is coming out of the coils? No one knows, not even Dynatec (I emailed them). I think the standard for the automotive world is around 36,000v assuming that they coils are getting 12v. But, when I measured the voltage going to my coils, it was, I think under 8v! Before someone chimes and says that bike is old, has bad wiring, etc, I measured this many years ago when the bike had around 6k miles. Because of the weakness of the ignition, I think iridiums can make a minor bump in performance, as a crutch for a weak ignition, but the difference is not going be as pronounced as cheap @ss copper plugs and relays. With the relays, the iridiums just serve as icing on the cake. Now, I'll say I have those nifty Dyntek coils on my bike so my ignition system.I don't think the aftermarket coils are needed, just get the relays.