Ok - Everyone - Please Help Me out.

I have a 2005 CBR600 F4i and I just changed Spark Plugs.

According to the Manual - fora 2005 CBR600 F4i I need NGK Iridium IMR9C-9H.

Stupid me - I bought NGK Iridium IMR9A-9H which is correct for a 2001-2004 CBR600 F4i.

Do I need to change these plugs ASAP or will it be ok.

The only difference between the C and Aaccording to NGK Website:

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

Firing End Construction:
A = Special Design
C = Special Design

SO WHAT DOES THIS MEAN - THEIR BOTH LISTED AS SPECIAL DESIGN. DO I NEED TO BE CONCERNED?

Both the thread and heat range is the same.

IMR9C-9H:
Extreme Long Life Laser Iridium Plug, 10mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Half Thread Type: 12.7mm (1/2") Threaded, 19mm (3/4") Total Reach, Resistor, Stud Terminal, Projected Tip, Iridium Tipped Fine Wire Center Electrode with Platinum Tipped Tapered Cut Ground Electrode, .035" (0.9mm) Gap. NOTE: Does not include terminal nut, if necessary, order part #067606-0051

IMR9A-9H:
Extreme Long Life Laser Iridium Plug, 10mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Half Thread Type: 12.7mm (1/2") Threaded, 19mm (3/4") Total Reach, Resistor, Stud Terminal, Projected Tip, Iridium Tipped Fine Wire Center Electrode with Platinum Tipped Ground Electrode, .035" (0.9mm) Gap. NOTE: Does not include terminal nut, if necessary, order part #067606-0051


IMR9C-9H
I = IRidium Platinium
M = 10, 19mm (3/4") Reach, 19mm Hex
R= Resistor Type
9 = Heat Range
C =Special Design
9 = 0.9mm (.036") (Wide Gapp)
H = 12.7 mm (1/2") (Thread Reach)

IMR9A-9H
I = IRidium Platinium
M = 10, 19mm (3/4") Reach, 19mm Hex
R= Resistor Type
9 = Heat Range
A =Special Design
9 = 0.9mm (.036") (Wide Gapp)
H = 12.7 mm (1/2") (Thread Reach)

 

I'm Trying to Debate whether it's worth driving 20 minutes (Round Trip) to buy the NGK Iridium Spark PlugsIMR9C-9H + spend another45 minutes to take out the IMR9A-9H Spark Plugs and replace them with the IMR9C-9H plugs.

Another site stated as long as the thread and heat range is the same - don't bother. The difference in power if any is not significant. In other words - don't bother - nothing it to gain from it other then getting to spend another 1hr on the bike.

Anyone have any other suggestions. Those with 2005-2006 CBR600F4i - have you install the IMR9A-9H Plugs instead of the IMR9C-9H Plugs?

 

This is a really minute issue, if an issue at all.

I think that as long as they share the .035' gap and heat range and such, you're just fine.

Does the bike feel differently with them? If not, don't sweat switching them out.

 

No - the bike feels the same if not better - being that I had 10K on the original plugs.

There both Gap at .035 and both Heat Range is at 9.

I think I'll call it a night and not worry about it.

If anyone else wants to chime in with their 2 cents - PLEASE DO.

 

I am no expert but I do not see any problem with running those. Like stated as long as they are gapped properly should be cool. I got 17k on my oe plugs.

 

According to the text, the IMR9C-9H has a tapered cut ground electrode, and the other one does not. I don't know how much that would change anything.

Personally I would ask if you can return them for the appropriate plugs. I'm no mechanic, so I don't like to differ from what's recommended.

 

I just looked at this again and noticed that they both have "c" as special design, but the one is "A" ?

 

My Bad - I've corrected it.

 

UPDATE:

Here's what the Technical Support Representative said about using these plugs:

Hello,

Thank you for contacting NGK spark plugs USA. Fortunately the IMR9A-9H can be substituted for the IMR9C-9H without any issues. The only difference is the IMR9C-9H has a taper cut ground electrode which helps to concentrate the spark more than on the IMR9A-9H. I would recommend you continue using the IMR9A-9H, but when replacing the plugs again you may want to get the correct IMR9C-9H because they may give slightly better performance. Hope this helps, thank you.

Regards,

BrandonPeeler
Technical Support Representative
Aftermarket Division
NGK Spark Plugs (U.S.A.), INC.
46929 Magellan Dr.
Wixom, MI 48393
Bpeeler@ngksparkplugs.com

and what Customer Service said:

Hello Mike,

These are essentially the same plug, the only difference is that the IMR9C-9H features a tapered cut shape ground electrode. All other characteristics, heat range, and gap are the same. The IMR9A-9H plug you purchased should work fine, although the tapered cut is to reduce quenching and shadowing. You can see the explanation here: http://www.sparkplugs.com/glossary.asp?kw=Tapered cut&manID=0&pt=1

Thank you.

Customer Service
ypriaulx@sparkplugs.com
888-800-9629

LOOKS LIKE I'M GOOD FOR NOW. In another 10K - I'll change them again but this time use the IRM9C-9H Plugs

 

This is kinda funny, something similar happened to me when brveagle and i were doing my 12k maintenance.........I am actually running 3 c's and 1 a.... notice no difference....I figure, same heat range, same specs.....its all good.