Single TB V7 plug caps.

[Vasco DG]

For people with single TB V7's who have issues with their crappy OE plug caps NGK XD05F caps work just dandy and fit under the covers. The XD05F's are Bakelite type rather than rubber. The only other thing you will have to change is the plugs Standard are CNR9EKB and you need to swap them to CR9EK's. The loss of the 'B' denoted a threaded terminal on the top of the plug and you don't use the little screw on widget. At least in our market you can't get the XD05E which would fit the wider top terminal of the original plugs.

Not sure if the V7-II uses the same plugs, I haven't checked, but I can't see any reason they'd change the plugs.

Pete

[sib]

For people with single TB V7's who have issues with their crappy OE plug caps NGK XD05F caps work just dandy and fit under the covers. The XD05F's are Bakelite type rather than rubber. The only other thing you will have to change is the plugs Standard are CNR9EKB and you need to swap them to CR9EK's. The loss of the 'B' denoted a threaded terminal on the top of the plug and you don't use the little screw on widget. At least in our market you can't get the XD05E which would fit the wider top terminal of the original plugs.

Not sure if the V7-II uses the same plugs, I haven't checked, but I can't see any reason they'd change the plugs.

Pete

Some confusion here.  My '13 V7 and '16 V7-II manuals say the stock plugs are CPR8EB9, not CNR9EKB, is this a typo in your post?  Second, the NGK XD05F cap is a resistor cap, with a 5K resistor built in.  However, the CPR8EB9 plug is a resistor plug.  Seems incorrect to have resistors in both the cap and the plug.  Please clarify.  Thanks.

[SmithSwede]

Thank you Pete! I have not been happy with the rubber OEM spark plug cap.  It does not fit well, and does not seem to stand the heat well.  Always a lot of voltage leaking black crap on the spark plug insulator.   I have twice tried to gently remove the cap from the plug to adjust valves, only to have the metal connector in the cap snap off.  I also wasn't keen on the $35 per unit price for a replacement.

I kept searching for a better plug cap.  You've found it.

[Vasco DG]

Yah, same problem I had with this bike. The original caps are sucky. Been too busy with my donor bike to check whether the original caps are a resistor type or not. If people think it's a problem? Just use a non resistor plug.  Something without an R designation.

Pete

[motofoto]

Can anyone confirm which is the correct plug to use with these caps? I'm going to give this a go this week.

[SmithSwede]

FWIW, I emailed the NGK technical service center about what plug would fit plug cap NGK XD05F and match the OEM spec CPR8EB9.  Here is their response:

We do have a plug which is threaded terminal, and non-resistor for you. C8E (stock# 7471). Same thread, hex size, and thread reach. Only difference will be that the center electrode does not protrude as far as the CPR8EB-9.

Thank You,
Lela Martin
NGK Spark Plugs, (USA) Inc. ||

[motofoto]

Thanks for the update.  FWIW, I tried the ones the OP mentioned, and it's running well.

[sib]

Seems to be true, although hard to believe, that NGK doesn't make a 120 degree offset spark plug cap identical to the XD05F but without a resistor.  About the C8E vs the CPR8EB9, the latter has a projected core while the C8E does not.  Even though the two plugs have the same heat range (NGK #8), the projected core plug will run hotter than the non-projected one at low RPM.  This could make a significant difference in low speed fouling.

[SmithSwede]

Moto Foto--just for clarity, are you saying that you are running the CR9EK spark plugs with the XD05F cap on your Stone, and it's working well?  How does the CR9EK compare, side-by-side, with the OEM recommended CPR8EB9, especially in terms of the spark plug tip projection? 

Sib--yes, I hear you about the lesser projection of the C8E compared to the CPR8EB9.   I'll probably try the C8E anyway, which may not be an issue for me since I do mostly high speed interstate travel.   And they are $2.50 per plug, as opposed to $5.50. 

But that's a good point---is anyone aware of an NGK, or other make plug, that would have the same kind of projection the CPR8EB9 has, but without the resistor and with the threaded (as opposed to solid) terminal?  Maybe it's what Pete said in the original post, the CR9EK, but I'm hardly a spark plug guru.   

All I know is that the OEM spark plug caps are suboptimal--loose fitting, easily broken, and prone to deposit a lot of black crud on the outside of the plug.   And stupid expensive at $35 apiece, compared to $5.50 for the bakelite XD05F.  So I'm keen to develop a solid work-around!   These stupid spark plug caps have been the only really "cheesy" and bad component I've encountered on the Stone. 

[Vasco DG]

The P stands for 'Protruding electrode' the B denotes the terminal type as being non removable.

[motofoto]

Moto Foto--just for clarity, are you saying that you are running the CR9EK spark plugs with the XD05F cap on your Stone, and it's working well?  How does the CR9EK compare, side-by-side, with the OEM recommended CPR8EB9, especially in terms of the spark plug tip projection? 

I am running that combo at the moment on my 2013 V7R.  The CR9EK did not extend as far into the combustion chamber as the original plug, and it had two ground electrodes instead of one.  It wasn't a match, but so far, it's running very well.  I'm going to keep a close eye on them, and see what's decided here.  If there's a better alternative, I'll switch again.  Next time I pull the plugs to read them, I'll take a photo of the difference.