Spark Plug

[knighttime]

NGK DPR8Z for the 400ex

Does anyone know any cross reference #'s for different brand plugs (splitfire, etc.)?? :confused:

[MIKE400EX]

I only use NGK's - personal preference. Don't bother with the Splitfire's, waste of money.

[ChadEXer]

Get the NGK DPR9Z. it lowers the head temp by 5 degrees. the plug is very close to where the vlaves seat and it will help your motor last longer!!!

[Ketch]

The Splitfire #SF416C That is what i'm useing.:D

Ketch

[Castor-426ex]

i also switched to the dpr9z i could tell a little difference between it and the regular plug

[knighttime]

:D

What's a spark plug???? :confused:

[2qk4u]

i just installed a 11:1 piston in my 400. can i and should run a DPR9Z plug. Do i have the clearance?

you can run that plug,,but it's recommended for long, high rpm, hot running motors, and big bore motors too,,,,most normal joe weekend riders don't need them. If your running a desert race or 2 hour GNCC race I guess you could,,,I'll probably always run the recommended spark plug in the 416..

[VegasEx'r]

Originally posted by Rico
What's a spark plug???? :confused:

It's a thingy used in diesel engines so that combustion occurs. EX engines run off of combustion. ;) :blah

[yellow machine]

I ahve run the staock plug for awhile, a sf416c splitfire, and an autolite plug that crossed into the dpr9z, to tell you the truth I have not noticed much difference between any of them. the next plug I am going to try is a Champion plug, it is called a Power Sport plug designed for atv's the number on these plugs is 8809 they are sold as a pair so you get a back up just in case. They are fine wire plugs, and are not supposed to get fouled out easily. On the 400, as hard as it is to start sometimes, this sounds like a good plug. I have to order them so I wont be able to report anything soon. but next month I am going to Little Sahara so I will put them through a tourtre test. You can probably find these at an auto parts store. I work at O'Reillys and I can order them. Hope this helped:D

[Deathbringer]

Run NGK.... screw the splitfire idea it just makes your wallet thinner. If you get a hopped up ignition coil with a lot hotter spark then the Splitfire "can" make a difference, but not with a stock ignition coil.

[400exJOE]

will the dpr9z make it harder to start becuase its a colder plug?

[RAPTORAZ]

I did a back-to-back comparison between the stock plug, the regular Splitfire and a Splitfire triple platinum. I noticed no diffference between the stock NGK and the regular Splitfire. But I did notice a little difference in throttle response from the Splitfire triple platinum.

[Woodsrider]

[QUOTE]Originally posted by yellow machine
[B]. the next plug I am going to try is a Champion plug, it is called a Power Sport plug designed for atv's the number on these plugs is 8809 they are sold as a pair so you get a back up just in case.

Your kidding right? I wouldn't run a champion in my lawnmower. let alone my EX, trust me champions are crap. They rank right up there with autolite:blah

[Wheelie]

400exjoe--

I could be mistaken, but a colder plug won't make your quad harder to start. A colder plug doesn't fire any colder, it simply disperses heat faster than a plug of a hotter heat range.