New Spark Plugs -- less power?

[woodcycl]

Since my 08 became new-to-me back in June and not being totally certain when the oil was changed, spark plugs, etc. ... i went ahead and took care of all those things. Changing the oil was the easiest ever on a motorcycle for me! Changing the spark plugs wasn't too bad either overall.

My question is this ... I ended up replacing my spark plugs with the OEM recommended NGK's. And, I noticed what I took out (and they were actually still good from what I could see) are NGK Iridiums. Funny thing is, and it could be only in my mind, but the bike doesn't seem to pull as hard/fast as it did prior to the change.

Thoughts?

 

[Zorlac]

Put the iridium's back in, they're better plugs.

 

[03HiYoSilver]

Also, you may want to check that you did not Pull One of the Spark Plug wires Out/Loosened of the Cap which Screws into them.

You did not mention how many miles are on the Bike... Iridiums are usually good for about 20-30k miles while the OEM are good to about 8-15k miles.

 

[woodcycl]

I wondered about the Iridiums. Okay, I'll put them back in and double check the plugs too. Thanks guys.

Edited to add ... bike only has ~12k on it so the Iridiums have plenty of life in them.

 

[woodcycl]

I put the Iridium NGKs back in and took out the non-iridium NGKs. I guess I can keep them and put them in in another 10k miles or so. Not sure yet if that was the problem in a lack of 'pull' or not, but hopefully that was it.

 

[RossKean]

I put the Iridium NGKs back in and took out the non-iridium NGKs. I guess I can keep them and put them in in another 10k miles or so. Not sure yet if that was the problem in a lack of 'pull' or not, but hopefully that was it.

As long as the plugs aren't defective and are in good condition, the iridiums will NOT yield any more power than a conventional copper core plug. The big advantage of the iridium plugs is longevity. I had a set in there for 35,000 miles and they didn't look terrible when they were changed out. I have conventional plugs in there now but will switch back to iridiums before the end of next season - I ride quite a bit and the longer-life plug has more appeal to me, despite the cost.

Ross

 

[Zorlac]

I put the Iridium NGKs back in and took out the non-iridium NGKs. I guess I can keep them and put them in in another 10k miles or so. Not sure yet if that was the problem in a lack of 'pull' or not, but hopefully that was it.

the iridiums will NOT yield any more power than a conventional copper core plug.

 

[SkooterG]

I put the Iridium NGKs back in and took out the non-iridium NGKs. I guess I can keep them and put them in in another 10k miles or so. Not sure yet if that was the problem in a lack of 'pull' or not, but hopefully that was it.

the iridiums will NOT yield any more power than a conventional copper core plug.

I don't buy that. I would like to see info provided by someone not selling the product. I don't see how iridium plugs will add any power. It's just a spark plug.

 

[Zorlac]

I don't buy that. I would like to see info provided by someone not selling the product. I don't see how iridium plugs will add any power. It's just a spark plug.

I dunno, it seems feasible to me.

 

[SkooterG]

I don't buy that. I would like to see info provided by someone not selling the product. I don't see how iridium plugs will add any power. It's just a spark plug.

I dunno, it seems feasible to me.

Interesting. Thanks for the link. Still skeptical, but I'll call it a 'possibly' now.

 

[UselessPickles]

Here's another interesting one: CLICK

Iridiums are the most consistent performers across multiple runs as the engine heats up:

 

[RossKean]

Frankly, I'm surprised that there was any measurable difference at all. Not sure about how the tests were done in terms of experiment design. i.e. random testing order vs sequential, repeats over various ambient conditions, and were they blind tests etc. In any case, for the latter UP post (which seems to be the most systematic comparison) the demonstrated improvement of just over 1% in output can't be much more than the limits of error and even if it is "real" I doubt that anyone could tell a 1% improvement in terms of driveability. Engine temperature, air temperature/humidity, fuel quality, altitude, atmospheric presure etc. would all have at least as much effect. - Not to mention the fact that the plug's behavior may be quite different (better OR worse) in the FJR engine compared to the engine used for the tests. Note: The comparison used is for PEAK HP and TQ (perhaps the only practical means of measurement). This does not translate into driveability under normal operating conditions. Perhaps a more meaningful value that would relate to a perceived power improvement would be the torque comparison for a throttle roll-on at 4000 rpm.

Again, having said all of this, I will go back to the CR8EIX plugs next year, not for power improvements but only for the fact that they should last longer.

Ross

 

[JR'SFJR]

I just installed Iridium plugs while doing another valve check and cct change out at 53k. Ran the stock plugs 27k, which still looked good and ran fine. Can't tell any difference with the new plugs.

 

[carlson_mn]

Just replaced the originals with oem plugs at 23k miles. No difference at all as far as performance. Zero visible wear on the original plugs.

 

[HotRodZilla]

The iridium plugs do not increase power. Maybe...Maybe a small percentage because of a slightly better spark, but nothing anyone would actually feel. The people selling them will claim gains all day long, but they want your money.

All iridium plugs will do is have some increase in longevity. Enough to offset cost? Some say yes, some say no. That's up to you.

As far as losing power after a plug change, if there was any power loss, it was due to something else.

 

[Zorlac]

A small percentage increase was all those websites ever claimed.

The narrow pointed iridium center electrode will arc over at a lower voltage than a more blunt electrode which possibly could advance the timing ever so slightly, maybe that's what the dyno's are picking up on?

In any event it's picking fly **** out of pepper but a 10yr service interval is right up my alley.