For NGKs, the higher the number, the cooler the plug. Some other brands work the other way.
NGK CR7EH-9 at advance auto parts for $5.99 ea. none in stock, have it in 24 hours
okmurdog
Will Ride for Pie
okmurdog
Will Ride for Pie
Is there anything wrong with using the Autolite equivalent?
Ken
Not that I'm aware...although I haven't used them, nor have I heard much about anybody using them. Personally, I'll stick with the Honda recommendations.
I sometimes get the 'bait and switch' tactic from auto parts stores regarding plugs or other items..."Yes, we have them"...when I get down there, it is a part from an aftermarket supplier. This is main reason I asked...
Let me help you with identifying NGK Spark Plug's. http://www.ngksparkplugs.com/docs/tech/partnumberkey.pdf
Go here for info on heat ranges http://www.ngksparkplugs.com/tech_su...x.asp?mode=nml
NGK recommends CR9EH-9 for our ST's. But wheres the fun in that? I say go with the "High Performance Iridium's" CR9EHIX-9's!
Go here for info on heat ranges http://www.ngksparkplugs.com/tech_su...x.asp?mode=nml
NGK recommends CR9EH-9 for our ST's. But wheres the fun in that? I say go with the "High Performance Iridium's" CR9EHIX-9's!
oops, cant figure how to delete this post, since i got all info in one above!.
I know this is an old thread, but I am due for plugs according to the maintenance schedule.
I wrote to NGK about the iridium option, and below is the answer I got (in less than 24 hours btw... I like that service)
Hello,
The Iridium plug will be an excellent option here as it will provide quicker starting and improved throttle response. The part number is CR9EHIX-9 stock number 6216
Best Regards,
Jason Norwood
NGK Spark Plugs ( USA) Inc.
Technical and Training Specialist - Aftermarket Division
46929 Magellan Drive
Wixom, MI 48393
Office: (248)-926-7107
Fax: (248)-926-6938
Email: jnorwood@ngksparkplugs.com
I wrote to NGK about the iridium option, and below is the answer I got (in less than 24 hours btw... I like that service)
Hello,
The Iridium plug will be an excellent option here as it will provide quicker starting and improved throttle response. The part number is CR9EHIX-9 stock number 6216
Best Regards,
Jason Norwood
NGK Spark Plugs ( USA) Inc.
Technical and Training Specialist - Aftermarket Division
46929 Magellan Drive
Wixom, MI 48393
Office: (248)-926-7107
Fax: (248)-926-6938
Email: jnorwood@ngksparkplugs.com
racinj
Jason Johnson
So how have they worked for you?
For a warmer climate, you would be best off using 8's or even 9's in the heat range...
The '-9' at the end CR8EH -9 pertains to the gap... The C is the thread size, R is resistor type plug, 8 is the heat range, E & H can't quite remember, but probably something to do with whether the electrode is protruding or not... And the -9 means that the plug gap has been pre-set to 0.9mm
The '-9' at the end CR8EH -9 pertains to the gap... The C is the thread size, R is resistor type plug, 8 is the heat range, E & H can't quite remember, but probably something to do with whether the electrode is protruding or not... And the -9 means that the plug gap has been pre-set to 0.9mm
The number at the end of the part number for NGK is the heat range not the gap. The insulator controls the heat range and is shorter or longer depending on the heat range.
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#32 is correct. The first number appearing in an NGK plug description is the heat range.
http://www.ngksparkplugs.com/docs/tech/design_symbols_plugs.pdf
I stand corrected it is the third character for heat range. 9 is what NGK indicates as the standard plug heat range (CR9EHIX-9) where a lot of shops seem to want to sell the slightly warmer 8 (CR8EHIX-9).
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Did the Honda recommendation change? My manual lists CR7s for normal use and 8s for extended high speed operation. I run 8s as they are easier to come by.
If you go to the NGK site and look up the ST1300 they say that the CR9EHIX-9 is the standard plug or equivalent since it is Iridium.
I put the CR8EHIX-9 Iridium plugs in my ST1100 and have almost 60,000 miles on them now. I have not seen any change in performance or gas mileage so they must still be workingAnd, they looked great last time I checked the gap etc.
I may change them when I do the 100,000 mile service in a few months but I?m not sure yet.
Rick
I just changed my plugs and installed the NGK CR7EH-9. The preset gap was within spec. However, I have noticed that my mpg has gone down, based on the mpg indicator. Any thoughts.
Is changing the plugs the only change you made? Any chance your thermostat may have failed? That's something you may not have noticed last summer but that would be more obvious in the cooler weather of spring?
I know the above post was from a very long time ago, but I wanted to provide some additional perspective on the question of which brand to use, especially since there are so many out there.
Referring back to Ken's question about the Autolite plugs:
Every time I've asked my various independent mechanics over the years about plug recommendations for my other vehicles ("high performance" engines like the HEMI or Cadillac Northstar as well as standard engines), the one consistent recommendation I've gotten is to stay away from the Autolite line. They've recommended other brands (Bosch, Champion, manufacturer OEM brands) but advised me to stay away from Autolite as they have seen engine problems develop, and view the Autolites as an inferior product. I don't know all the details, but this is from guys I trust that have a lot of experience.
I also am beginning to gather parts for my ST's 24k service and checked with a local independent about what they put into motorcycles. They do the NGK line across the board, and also recommended staying away from the Autolite line. If a person is looking for a little hotter temp and better performance (which would be helpful at the higher altitudes in Colorado!), they recommend the iridium tip. I'll be getting a set for my ST and am hopeful that they will help solve the "running lean" issue that was noted at the local dealership when I had my clutch serviced a couple weeks ago.
---------------
BTW - many thanks for the reference links in several of the previous posts - very valuable info!
Referring back to Ken's question about the Autolite plugs:
Every time I've asked my various independent mechanics over the years about plug recommendations for my other vehicles ("high performance" engines like the HEMI or Cadillac Northstar as well as standard engines), the one consistent recommendation I've gotten is to stay away from the Autolite line. They've recommended other brands (Bosch, Champion, manufacturer OEM brands) but advised me to stay away from Autolite as they have seen engine problems develop, and view the Autolites as an inferior product. I don't know all the details, but this is from guys I trust that have a lot of experience.
I also am beginning to gather parts for my ST's 24k service and checked with a local independent about what they put into motorcycles. They do the NGK line across the board, and also recommended staying away from the Autolite line. If a person is looking for a little hotter temp and better performance (which would be helpful at the higher altitudes in Colorado!), they recommend the iridium tip. I'll be getting a set for my ST and am hopeful that they will help solve the "running lean" issue that was noted at the local dealership when I had my clutch serviced a couple weeks ago.
---------------
BTW - many thanks for the reference links in several of the previous posts - very valuable info!
I'm weird about plugs, Motorcraft for fords, NGK's for most japanese, Delco in GM's, Bosch in germans..... I'll switch up if I can't get my preferred brand, except in Japanese, I always run NGK's....
Place I used to work had a house brand plug that the boss insisted on using, I argued, he's the boss, he won. Until a vehicle that required an immense amount of work to change the plugs came back with a bad misfire. I tore it down, found the culprit plug, swapped out for my choice. Then, he said, because it was warranty, no $$$ in my pocket. I argued and won...... After that, he let me pick my brand, of course, the premium price was reflected in the bill. If a customer wanted cheap plugs, no biggie. In big bold letters, on the invoice "CUSTOMER DECLINED FACTORY PLUG, NO WARRANTY ON INSTALLED PARTS OR LABOR"
Place I used to work had a house brand plug that the boss insisted on using, I argued, he's the boss, he won. Until a vehicle that required an immense amount of work to change the plugs came back with a bad misfire. I tore it down, found the culprit plug, swapped out for my choice. Then, he said, because it was warranty, no $$$ in my pocket. I argued and won...... After that, he let me pick my brand, of course, the premium price was reflected in the bill. If a customer wanted cheap plugs, no biggie. In big bold letters, on the invoice "CUSTOMER DECLINED FACTORY PLUG, NO WARRANTY ON INSTALLED PARTS OR LABOR"