NGK Spark Plugs

[Mike V]

All!
I just got off the phone with Rick Jones at Mottorad Elektrik regarding the NGK application for our 650's. Rick informed me his web site reference of the NGK BP8ES is a MISPRINT! I think a lot of confusion may have originated here since a lot of suppliers have referred to Rick's website for distribution of plugs, at least that's what happened in my case.
 
Should be NGK BP6ES for the straight conversion from the Bosch W6DC.

Rick sends his appologies since he doesn't do the web editing on his site and asked I get the word out.

Hope this clarifies some things. Sometimes you just never know until you ask.

Bob, he says a good plug for you to use in the AZ summer heat would be the NGK BP8ES with constant Interstate speeds and high temps.

Mike V.

[Bob_Roller]

Thanks for the info Mike !!!!!

[Semper Gumby]

I switch from the W5DC to the BPR7EIX Iridium with 0 ohm plug caps from NGK.  The plug cap part number is LZFW.  I've had these Iridiums in since Decmber of 2006.  They have got 25,000 miles on 'em.  I need to bead blast the outside as they are rusting.

Gap is set to .025".

They run really clean so I might try a set of cooler BPR8EIXs next time.

[nhmaf]

I've used the NGK BP6 and BP7 plugs with 5K ohm resistor caps, and haven't noticed any problems with either.  Both seem to keep their noses (insulator around electrode) pretty clean, which is the principle reason for specifying the temp range of the plug (to burn off deposits to keep them from accumulating and impairing the spark).

As Barry notes, using resistor plugs with resistor caps (Assuming nominal resistances of 5K Ohms or so) will still work fine in most cases, tho the spark will be a bit weaker and longer duration because the additional resistance increases the time constant of the circuit TC = L/R where L is inductance of the secondary coil and R is the total series resistance).   The best performance is with only 1 resistor (either in the cap or in the plug) but if one is in a pinch, running with (2) won't do any harm until more optimum components can be installed.