Spark Plug 101

Wisdom needed.

Called the shop for new plugs and learned that there are CR 7's 8's and 9's based on heat ratings.
?
Any thoughts? Not sure which ones I have in there now, but I run in temps from 32 to 100 and up. What to do?

According to the manual the cr7 is the standard use plug. The cr8 is for continued high speed riding. You can get a competent tech to read the plugs you now use and they should be able to advise you from looking at your present plugs as to which is best.
Sonny

Lots of good info about heat ranges on the NGK Sparkplug site

including how to decode (NGK) spark plug numbers.

I use the iridium CR8 available from www.tucmoto.com. Click on club specials and then on STOC. They are the same plugs that fit the ST1100. You can get these iridium ones for less there than the dealer gets for the standard plugs! The slightly colder 8 heat range should be OK as precious metal plugs generally have a wider heat range anyway. If you go to the plug manufacturer's site and drill through the applications for the ST13, this plug is the recommended one. I've got about 16K on a set of these and she just purrs!

Thanks.
That's all good advice. I guess I just need to determine what Honda means by extended high speed riding. I never ride around town..just long trips. Maybe the higher heat rating will work better for me. I'll check out the links.
BTW, Jeff, which gap do you use...the Honda Manual or the NGK spec... (.035)?

LT Rider said:

Thanks.
That's all good advice. I guess I just need to determine what Honda means by extended high speed riding. I never ride around town..just long trips. Maybe the higher heat rating will work better for me. I'll check out the links.
BTW, Jeff, which gap do you use...the Honda Manual or the NGK spec... (.035)?

Click to expand...

LT, higher number = lower heat range in NGK's nomenclature. I've no idea why they do that this way as it's confusing. Some plug manufacturers are the reverse even. In this example then, the CR7 is hotter than a CR8 and a CR9 is colder than an 8. Be careful about that. Highway (high speed) riding on a hotter plug (lower number) would be a mistake and not a good thing. It sounds like you will be fine with "higher number" plug from NGK which would be a colder heat range.

For the gap, I just go with what Honda says, I didn't realize there was a discrepancy between NGK's and Honda's recommendations?

wjbertrand said:

For the gap, I just go with what Honda says, I didn't realize there was a discrepancy between NGK's and Honda's recommendations?

Click to expand...

I guess I'm not sure if there is a discrepancy....it seemed there was at first read-through, but the truth is I'm confused. Spark plug 101 is kicking my *** and I'm too lazy to go dig out my manual a second time.

I went ahead and ordered the OEM "7" and will just stay the course and go ride. Thanks again for all the good instruction.

Standard range plugs should just work fine. The heat in which you ride has no bearing on the heat range of the plug. At sustainted heavy work (eg on a dyno flat out, race track or continuational flat out speed you MAY need colder plugs. My only experience with colder plugs is that they foul up in normal use. One stage colder on the ST13 does not seem to cause issues. Go ride is the best idea.

OK.

It was suggested on another thread that I upload these images, but it made more sense to me to include them here.

These plugs had 31k on 'em. They are Denso U22FER9s and are the OEMs. The power on and off and hesitation that has made my ST so un-Hondalike all these miles is probably the result of several issues. The most improvement came from replacing the stuck open thermostat. Riding above 5,000 feet in the rain at 45 degrees outside really made it run poorly. The dealer that did the work would have replaced these plugs, but they were out of stock. I rode home (1,500 miles) and my local dealer was also out. That's when I began this thread.

I mail-ordered the NGKs after reading the above advice. But,,,I had a ride to take so I removed the ones you see below and cleaned them with a wire brush, 140psi air hosed 'em and checked their gaps and kept on truckin for another 1000 miles or so.

The other day, the new NGKs arrived and I put 'em in. I followed the manual's instruction and all is well. I also added Seafoam treatment (for the first time) and left on another ride. It is now 1000 miles later and the bike really performed well this past weekend. We rode two-up at every speed and from 600 feet to 7000 feet altitude. The bike still runs best below 4000 feet, but the new plugs and Seafoam must have helped some. The hesitation that I don't like on this bike is still there however. It is the same hesitation that my '03 VFR had and why I got rid of it.

I really think Honda just hasn't figured out fuel injection yet. Too many riders of the 13 are having the same symptoms, but for what it's worth, the new plugs, Seafoam, new thermostat, Turbo City Fuel Pressure Regulator, Audiovox Cruise Control and setting the idle at 1300 RPMs has kept me going and that's good enough for me until the next bike.

So if anyone would like to read the plugs and offer advice, Sparkplug 101 is still in session.

Let's Ride!

Those plugs look almost perfect.

This might help

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

I ran 8's in my 05... also had McCruise and TT's FPR too. I rode for a week in the CO mountains without an issue back in 2006.

I ride frequently with ST's in the 10k+ ft range, and they don't seem to have issues. I wonder what plugs they are running

I'm running the Iridiums in both bikes. Put a new set in ReSTored when I got her 5 years ago and have added 83,000 miles with no problems. They look like they'll last forever, which is good, cause the bike looks like she'll last forever, too.

The plugs in the pics look great....
Crappy wet weather performance is usually due to plug WIRE problems, not plugs. Honda is notorious for poor wires.
There is very little noticeable difference in operation due to different heat ranges...although I would suggest that the coldest may foul a bit quicker.
The little darker areas might be corrected if you were to index the plugs, but not a noticeable improvement either.
Some of the newer plugs (Iridium sp?, ie) offer considerably better performance according to the techies at BMW NA....both cars and bikes....

Just a bit to add to the spark plug 101. I searched the ST site and people recommended to use anti-seize on the spark plugs. I was doing some searching and came across the below from NGK which is the brand people are recommending we use. They say not to use anti-seize on the first install for the reasons stated below, but OK to use on re-install. Comments?

Topic
The use of anti-seize compounds on spark plug threads that have a “special shell
plating” (i.e. Trivalent coating).

Issue
Applying anti-seize to the treads of spark plugs that have a special metal plating
thus allowing the installer to mistakenly over-torque the spark plug in the cylinder
head. Over-torque stretches the metal between the last thread and the seal
between the cylinder head and spark plug, causing a much higher probability that
the spark plug will either break during installation or upon removal.

Solution
For spark plugs with special metal plating; do not use anti-seize on the initial
installation. If a spark plug with special metal plating is removed and re-installed,
only then should anti-seize be used prior to “re-installation”.

Additional Information
It is recommended to use spark plugs with the special plating on all aluminum
cylinder head applications to prevent damage to the cylinder head. The shell
plating acts as a “lubricant” which breaks away from the main body of the spark
plug during removal thus preventing the bonding of the aluminum from the
cylinder head to the threads. All NGK Spark Plugs are manufactured with special
shell plating on the metal body.

The use of anti-seize on spark plugs is only recommended on those brands that
do not offer a special metal shell plating. Spark plugs that have a shiny silver
appearance on the metal body usually indicate that the spark plug is
manufactured with special metal shell plating. All spark plugs that have a
blackened or dull appearance on the metal body offer no protection against
seizing or protection against bonding to the aluminum cylinder head.

Taken from here: http://www.ngkplugpro.ca/content/contentfiles/pdf/NGKSP-0907-1-Anti-SeizeonSparkPlugs.pdf

LT Rider said:

OK.


I really think Honda just hasn't figured out fuel injection yet.

Let's Ride!

Click to expand...

I've had 2 ST1300's and they run just fine right out of the box.
robert

Overtorque? Much like an oil filter, do not torque it on, just turn in until gasket is seated on base, then turn 1/2 turn more. On second use plugs, I do 1/4 turn as gasket is partially crushed from the first install. No worries. I use anti-seize anytime steel is in contact with aluminum where I might risk an expensive repair such as an engine, or if that fastener may not be removed for the next season or so. I use blue loctite on stainless tupperware screws though its probably not necessary (careful not to get it on the plastic).

Sorry to hear your ST is tempermental with altitude. I did a long ride this summer over several high mountain passes ( 10,000 feet, Bear Tooth, etc.) with absolutely no issue, and about 100 lbs of gear, and my 170 lbs of not so lean beef. No issues; perhaps you need a fuel regulator or mixture adjustment. At any rate, elevation is usually not a deterrent to the ST1300. I use stock Honda plugs.
Good luck.

LT Rider said:

Wisdom needed.

Called the shop for new plugs and learned that there are CR 7's 8's and 9's based on heat ratings.
?
Any thoughts? Not sure which ones I have in there now, but I run in temps from 32 to 100 and up. What to do?

Click to expand...

Hot weather riding needs a colder plug. I'm in Texas and it gets into the triple digits quite often in the summer months. I just got my bike back from the dealer today and they put in CR9EH9 plugs. Then when I went to the NGK website to check the standard plug for the ST1300, it showed the same CR9EH9. I guess the big engine develops more heat and uses a cooler plug as standard.

http://www.ngksparkplugs.com/part_finder/motorcycles/step4.asp?id=1751&type=reg

Best regards,
John