Updated Spark Plug Information

[knyte]

26 minutes ago, texscottyd said:

it's always welcome here

Agreed; if someone finds a platinum or Iridium plug that runs well in our bikes, I'd totally swap them out!

[2and3cylinders]

3 hours ago, knyte said:

Agreed; if someone finds a platinum or Iridium plug that runs well in our bikes, I'd totally swap them out!

I didn't note any issues running the CR9EIA-9 (Stock # 6289) which looked good after 8,000 miles), I just didn't feel comfortable continuing with them given their shorter reach; and then there's their higher cost over the OEM... 😆

[knyte]

7 minutes ago, 2and3cylinders said:

didn't feel comfortable continuing with them given their shorter reach

Exactly.  OEM engineers usually understand the tolerances and whatnot far better than I, so I tend to stick with whatever they recommend (as a general guide).

8 minutes ago, 2and3cylinders said:

then there's their higher cost over the OEM

Personally I'm fine with the higher cost IF the economy is there - ie longer plug change intervals.

[2and3cylinders]

41 minutes ago, knyte said:

Exactly.  OEM engineers usually understand the tolerances and whatnot far better than I, so I tend to stick with whatever they recommend (as a general guide).

Personally I'm fine with the higher cost IF the economy is there - ie longer plug change intervals.

I think it would be a wash.  Also, I'm not going to stretch checking the plugs more than 10,000 miles anyway, which I can do by just tipping the radiator down.  I can check TB sync with the extension lines I plumbed accessible without touching anything else.  Now I've also reduced valve lash check to 20k miles max, so if I'm going to be in there anyway, I'll clean/replace the air filter, plugs, check the TB sync and lube the linkage...

[PhotoAl]

Very interesting discussion, thanks OP for posting up.  I wrote iridium plug off after running them in my 2012 CBR600RR.  Ran them a little shorter than normal cycle as it seemed like it wasn't running as well as the OEM plugs.  Good to see the points made here and have stored up my interest in them again.   

I ran the OEM pugs in my 2020 Tracer 900 GT for 12,000 miles and they looked very nice and the bike ran well.  Most of the miles on my bike are long trips with lots of time running on the open road getting "there" or coming back.  So more time in higher gears and less revolutions and fewer sparks than say a bike which see more local riding with more time spent in lower gears and accelerating.

Totally understand they service intervals and know they are designed to cover all types of use.  Therefore and not concerned about running them 11,000 miles compared to recommended 8,000 miles.  After the "11,000 mile service" I did on the bike I took a 6,400 mile trip. I did replace the air filter since was in there - it looked fine but replaced anyway.   Now at 18,000 miles going to check valve clearances but will probably not change the plugs.  

[skipperT]

I agree, this has been a good discussion. 

Even though Yamaha recommends 8k miles, the conventional thinking is they could surely be extended to 12 or 16k miles. I’d love to see some people post up pics of their stock CPR plugs at 16 and 20k miles. My guess is that they will look clean as a whistle, but I’d be curious to see if the center electrode has worn noticeably such that the gap has increased so that it’s out of spec. Then we would have a good idea how long the stockers could go. YMMV of course. 

I’ve pushed mine to 12k without issue. 
-S

[betoney]

1 hour ago, skipperT said:

Even though Yamaha recommends 8k miles, the conventional thinking is they could surely be extended to 12 or 16k miles. I’d love to see some people post up pics of their stock CPR plugs at 16 and 20k miles. My guess is that they will look clean as a whistle, but I’d be curious to see if the center electrode has worn noticeably such that the gap has increased so that it’s out of spec. Then we would have a good idea how long the stockers could go. YMMV of course. 

I’ve pushed mine to 12k without issue.

I have posted photos of mine before though I don't have the photos saved anymore.

I change mine when bike is apart for the valve inspections,- 23k, 44k and 64k.  Each time the mechanic has inspected the gap and electrode for wear and edge sharpness and said they were still in spec and barely showing any visible wear.

I have asked him if he recommends changing them sooner and he said -for my bike- based on the trend he has seen over the past 5 years of servicing it, there was no reason NOT to stick with the 20-22k replacement schedule.  Other owners will want to use their own judgement or mechanics recommendations.

[piotrek]

I fell for this once (culprit thread), and certainly understand the temptation. Bike worked well for 3 years on the iridium plugs, and then it suddenly didn't. Ordeal documented here. The fix was to go back to OEM spark plugs.

There is no updated spark plug information from either NGK nor Yamaha. Sales people be sales people... they're there to sell stuff. 😜

[Ride On]

On 1/15/2022 at 8:18 AM, skipperT said:

I agree, this has been a good discussion. 

Even though Yamaha recommends 8k miles, the conventional thinking is they could surely be extended to 12 or 16k miles. I’d love to see some people post up pics of their stock CPR plugs at 16 and 20k miles. My guess is that they will look clean as a whistle, but I’d be curious to see if the center electrode has worn noticeably such that the gap has increased so that it’s out of spec. Then we would have a good idea how long the stockers could go. YMMV of course. 

I’ve pushed mine to 12k without issue. 
-S

Here's my factory plugs at 22,500 miles.  Easily could have gone longer but conveniently changed them out with stock plugs when I reset the valve clearances. 8 out of 12 valves were tight, several exhaust valves down to .005".

[peteinpa]

Color is good, can't zoom pic well enough, but center electrode looks rounded.

[skipperT]

4 hours ago, peteinpa said:

Color is good, can't zoom pic well enough, but center electrode looks rounded.

Agreed, those have some wear to them. 
-S