Diff Betx Cr9e And Cr9eb

[Tan Kay Chuan]

The Yamaha FX uses NGK CR9EB spark plugs. I checked the NGK web site. The only application for CR9EB is the Waverunner PWC. Whereas CR9E has numerous applications including the Yamaha R1 motorcycle engine. My question is "Is there any real difference between the CR9E and the CR9EB?" NGK specifies the additional "B" as special. But it does not say special in what way. Maybe it is special because they charge a higher price for the CR9EB spark plug.

Anyone has additional information on this. Thanks.

[RiverDad]

Re: Diff Betx Cr9e And Cr9eb

G'day TKC,

I saw this also when I went looking for a Iridium plug for my FX 160. "B" denotes special design.

The plug for the M-1 engine verses the R-1 might need a shorter reach plug ? Piston dome might dictate this ..but who knows ...the compression is the same in both engines (circa 11.9:1).

The only real answer would be a call to an NGK tech in local area or try to compare the two plugs at a place that stocks both ???

Interesting outcome if you can get to the bottom of it ....

Regards
Anthony

[Tan Kay Chuan]

Re: Diff Betx Cr9e And Cr9eb

I called tech dept at NGK. CR9E comes without a plug at the top of the spark plug. CR9EB comes with a permanent plug at the top of the spark plug. He says that's the only difference. The only high performance spark plug that can be corss-referenced to the CR9EB is the Denso Iridium IU27.

[Bill O'Neal2]

Re: Diff Betx Cr9e And Cr9eb

C= 10mm Thread diameter
R= Resistor type
9= heat range
E= 19mm thread length
S= Special construction for specific application ( could mean several differet things, any of which is only designated as "special".

B= special also, but in my NGK book, a "B" designates that it fits a Honda CVCC

It sounds like in this case, "special" means it doesn't have the little screw-on or permanate copper cap on the top of the sparkplug that connects it to the sparkplug boot on the end of the sparkplug wire leads.

[RiverDad]

Re: Diff Betx Cr9e And Cr9eb

I finally got to chat with an NGK engineer as well. The "B" denotes (in this case) an integrated terminal. That is .. the large terminal that usually screws on is integrated with the core conductor. Least they agreed !:)

This is to decrease resistance that might occur with a threaded terminal that screws on ..if it comes loose. The high energy coil plugs straight onto the terminal and is more efficient if the terminal is a better conductor by being integrated.
He also informed me that an Iridium equivalent is not yet available ..as you said above ...

Have a look at spark plug torque and its relationship to heat transfer on the site. I used a torque wrench set at 9ft lbs to do mine up. Be careful with the small electrical connectors that supply the coils ..they have a small rubber boot thats delicate and the clip tang pushes in to release ...only finger pressure is needed to release ...no pliers or tools !!

The coil rod needs a slow firm twist left and right to pop them out ...go easy on the upforce ...twist slowly but firmly while applying upforce. Once again fingers only is needed ...no tools !!

I applied Dow Corning "o"ring and seal lubricant to the top "o" ring area only ...go easy with amount ..just a smear to create shine on "o" ring is all that is needed ... creates a good seal that releases easier next time ...


Regards
Anthony