Topic: Spark Plug Difference ?

[rddcw]

I pulled the spark plugs out of my 74' CB 750 K4. They were NGK D 8EA ?  Manual calls for NGK D 8ES ?  Does anyone know the difference and what this bike should have ?

[flybox1]

NGK D8EA and Denso X24ES-U are the recommended plugs

[madmtnmotors]

I prefer the Denso's myself.

[rddcw]

Thanks Flybox1 for the info. I reads a little more Posts and saw that Hondaman recommended Nippon Denso X24ES-U as well, so ordered those just now thru spark plugs.com.

Is there a gasp you would recommend me setting these plugs at?

[flybox1]

I was a fan of denso's until i had starting issues.  i switched back to the D8EA's and the hard starting went away.
gap per the manual (.024" - .028")  I check that all mine are .024"

cheapest place to get denso's is rockauto.com
$1.31

[Deltarider]

If you can find them, the NGK D8ES-L was a good plug too and was prescribed for almost all SOHC Fours.
BTW, many CB500/550 owners here used them as well.

[PeWe]

The resistor version is still available
http://www.ebay.co.uk/itm/4x-NGK-Copper-Core-Spark-Plug-DR8ES-L-DR8ESL-2923-/230793882396?hash=item35bc632b1c:m:mfJ81juJZWAWBwD8iVw8AFA

I'm convinced that resistor plugs and NGK 5kohm caps will not work that good.
I tried Denso Irridium (resistor) plugs earlier this year that did not work well with my NGK 5kohm caps. NGK D8EA better.
0 ohm caps to be found?

I use NGK D8EA now.

[Garage_guy_chris]

Here is the decoder for NGK it explains the part numbers:

http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

And here is the decoder for Denso plugs it also explains there part numbers

http://www.globaldenso.com/en/products/aftermarket/plug/spec/

[Duke McDukiedook]

The resistor version is still available
http://www.ebay.co.uk/itm/4x-NGK-Copper-Core-Spark-Plug-DR8ES-L-DR8ESL-2923-/230793882396?hash=item35bc632b1c:m:mfJ81juJZWAWBwD8iVw8AFA

I'm convinced that resistor plugs and NGK 5kohm caps will not work that good.
I tried Denso Irridium (resistor) plugs earlier this year that did not work well with my NGK 5kohm caps. NGK D8EA better.
0 ohm caps to be found?

I use NGK D8EA now.

Try the non-Iridium plugs. For whatever reason someone may chime in on iridium plugs do not work well on these machines.

[gtmdriver]

Here is the decoder for NGK it explains the part numbers:

http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

And here is the decoder for Denso plugs it also explains there part numbers

http://www.globaldenso.com/en/products/aftermarket/plug/spec/

When I bought my CB350F a couple of months ago it had a misfire on one cylinder. It didn't take long to spot that number 3 spark plug cap was arcing to the cylinder head. When I checked I found that resistor plugs had been fitted along with the standard resistor caps. As soon as I changed the plugs to non resistor equivalents the misfire and arcing cleared completely.

I subsequently changed the plug caps too.