Iridium Spark Plugs

[Tortuga]

This and other forums rave about Iridium plugs for Nomads. Mine is a 1600. Where, exactly, do you find the DPR7EIX-9 specified for a 1600 Nomad. I can't find it anywhere so far. Surely I must be doing something wrong in my searching. I've even queried NGK with no luck.

[DragonLady58]

They have them at Dennis Kirk, Amazon, but I always usually getting plugs, I get a set thru O'Reillys first.....don't know how they were treated....
https://www.oreillyauto.com/detail/b...g/7803/4537496

[BrokeAss]

https://www.ebay.com/itm/2-pcs-NGK-7...sAAOSw85tfPjCQ

[Tortuga]

No, no. I know where to buy them. My question is why can't I find anything in print that says this plug is the plug for a 2006 Nomad 1600. I see 1500's but not 1600's. One place said this plug doesn't fit your bike, or words to that effect. Who says it's good to go and where does it say that? NGK doesn't seem to say it.

[DragonLady58]

OK T, I understand.....look at your book, see what plugs you got in your bike. Now, Look up the plugs for a 1500.....the same.....same engine....
Plugs are the same, pistons, cylinders, only diff. is the more rounded head covers, and the crankshaft....

[ringadingh]

They will fit a 1600 motor, I use those in my bike.

[BrokeAss]

Simple, the DPR7EIX-9 is the iridium varient of the DPR7EA-9.

[Jllm02199]

I use them all the time. I have 1600 motor in my 02.

[Tortuga]

Well, NGK responded by saying the plug "could" work. How's that for a glowing (no pun intended) recommendation. They say it's colder than stock plug and may result in fouling and that there is no iridium match for the stock plug and they can't guarantee plug life.

[Jllm02199]

Originally Posted by Tortuga

Well, NGK responded by saying the plug "could" work. How's that for a glowing (no pun intended) recommendation. They say it's colder than stock plug and may result in fouling and that there is no iridium match for the stock plug and they can't guarantee plug life.

So much for them knowing anything about their plugs.
DPR7EA-9 is stock plug. DPR7EIX-9 is iridium.
The 7 is the heat range.

[Tortuga]

Hmmm. My owner's manual (2006 1600 Nomad) says the DPR6EA-9 is the stock plug. So much for Kawasaki and NGK getting it wrong I guess.

[Jllm02199]

Originally Posted by Tortuga

Hmmm. My owner's manual (2006 1600 Nomad) says the DPR6EA-9 is the stock plug. So much for Kawasaki and NGK getting it wrong I guess.

That’s strange, my bike had Dpr7ea_9 in it from the start.

[Sabre-t]

If your manual calls for the NGK plug with a 6 heat range (lower is hotter in the NGK scale), a 7 is marginally cooler than a 6, so if you go with the DPR7EA-9, you could probably go with a lower octane gas. A cooler plug or a higher octane will retard ignition. If you cool the plug, you should reduce the octane to compensate. That would prevent fouling from the cooler plug, but you would get the long life benefit of the iridium plugs.

[nomadbob]

I got mine at Advance Auto Parts.

[andyvh1959]

Originally Posted by Sabre-t

If your manual calls for the NGK plug with a 6 heat range (lower is hotter in the NGK scale), a 7 is marginally cooler than a 6, so if you go with the DPR7EA-9, you could probably go with a lower octane gas. A cooler plug or a higher octane will retard ignition. If you cool the plug, you should reduce the octane to compensate. That would prevent fouling from the cooler plug, but you would get the long life benefit of the iridium plugs.

Hmm,....can't quite agree. A "cooler" plug means the plug itself holds less heat, which could reduce the speed of the flame front, the time it takes for the entire flame front to move across the piston. If that's what you mean by retard ignition. It slows the flame but does not actually "retard" the ignition. And yes, a reduced flame speed can reduce the effects of pre-ignition, pinging. As far as selecting lower octane fuel that is sketchy as there usually is Premium (hopefully whole gas) at around 91 Octane. Next choice is 10% ethanol blend which is 87 Octane. Depending on where you live (like here in Wisconsin) you can find a few fuel outlets selling 87 Octane whole gas, like at Cenex, but it's rare. But certainly do NOT use any 88 Octane blend, which is 15% ethanol.

Given that the VN1600 runs at over 9:1 compression ratio you can try lower octane and if it doesn't ping then the plugs are helping out. If it pings at all your only choice it to go back to higher octane premium or use an octane booster.