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Spark plug query


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Hey folks, beginner questions here but we all have to start somewhere, right? 

 

Changed my rear spark plugs today, and they were oily, and the electrode was very thin. Also some oil visible around where they screw in. The bike is (well, was) running well with no starting issues or lumpiness so should I just leave well be and check my plugs regularly, or is action needed? 

 

Secondly, with regards to the front plugs the Haynes manual says to unbolt bottom fixing of radiator and swing forwards to "improve" access. Is this a joke, there's no way I'm getting a plug out of that gap, thinking I'll have to unbolt and pull radiator fully forwards, or am I just being a chump?

 

All help much appreciated 😁

 

 

20210413_192027.jpg

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Oily doesnt mean the plugs are bad. But since you already bought new ones, you might as well fit them

Check the partnumber on the plugs. My bet is the left one is an irridium one...

 

 

 

My guess based on have bought irridiums for my VFR :laugh:  They should last some 25k km's...

I changed them because the bike had an unknown service history when I got it and had stood idle for 4-5 years

IMG_20200902_144029.thumb.jpg.54b5e72ca9fa9f372c6e4cb013048aa8.jpg

 

 

 

 

As for the front radiator, if I can, so can you...

I used a wooden wedge, tapped it between radiator and engine head....  But if not comfortable with that, unbolt the lot

 

Torque them at 12Nm.

 

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Yes, easiest to remove entire engine 1st. Then replacing plugs is simple.

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4 hours ago, Dutchy said:

Oily doesnt mean the plugs are bad. But since you already bought new ones, you might as well fit them

Check the partnumber on the plugs. My bet is the left one is an irridium one...

 

 

 

My guess based on have bought irridiums for my VFR :laugh:  They should last some 25k km's...

I changed them because the bike had an unknown service history when I got it and had stood idle for 4-5 years

IMG_20200902_144029.thumb.jpg.54b5e72ca9fa9f372c6e4cb013048aa8.jpg

 

 

 

 

As for the front radiator, if I can, so can you...

I used a wooden wedge, tapped it between radiator and engine head....  But if not comfortable with that, unbolt the lot

 

Torque them at 12Nm.

 

 

 

Iridium plugs! That makes me feel much better, never seen one before but that's obviously what they are. Follow up question then, having read that Iridium plugs are longer lasting and can offer better performance, but not necessarily with older vehicles, would I be better putting in the new copper plugs or putting back the old Iridium ones? They've probably done a couple of thousand miles at most.

 

As far as the radiator goes, I'll give it another go and try and be a bit braver about shoving it out the way. Unless of course your answer to the above question is stick with the Iridium, in which case problem solved!

 

Thanks for the help, much appreciated 🙂

 

 

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2 hours ago, VFR78 said:

Iridium for my bikes always.

 

they say that shit comes from cosmic outta space, ya no ? 🤪

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Seriously, kosmos is the source.

Thing with iridium plugs they have huge gaps made to work with modern high energy coils. This is where performance comes from. For older bike I would gap them to match output of existing system...

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2 hours ago, Magneto said:

Seriously, kosmos is the source.

Thing with iridium plugs they have huge gaps made to work with modern high energy coils. This is where performance comes from. For older bike I would gap them to match output of existing system...

Can't say I agree Magneto. The NGK Iridium equivalent for the standard CR8EH-9 is the CR8EHIX-9 both of these plugs have the same electrode gap of .9mm.

The Iridium CR8EHIX-9 has a life of 50,000 miles.

The original CR8EH-9 good for around 30,000 miles. According to the NGK specs.

 

Guess the important thing for the OP is to check that the correct Iridium equivalent has been installed and how many miles have they done.

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This was inevitable at some point Grum, it’s cool. ;-). Note I am talking in general about older bikes, that often have smaller gaps. If there is a direct replacement Iridium plug for the application that is great, I would still check the gap...

 

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I  would go with what the manual asks for in this case. Bike ran great from the factory with the copper plugs, so the factory called for copper plugs are fine. No need for pricey Iridiums.

When I got my 5th gen VFR800 I bought a set of the NGK's it calls for in the manual and when I took out the plugs that were in the bike I noticed they were Iridiums. I put in the normal NGK plugs and was fine.  

 

...and it never hurts to check the gap of the plugs before you install them. You never know. 

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Some great advice and information here, thanks folks. I think at this point I'm going to stick the original iridiums back in. They look pretty and good haven't had many miles on them - I've done fewer than 3000 since 2013 when she had a major service and these were probably fitted, and it gets me around the issue of getting at the front plugs. Also, as mentioned above, the bike was running very nicely as she was.

 

I'll keep the coppers I've got for next time, or if I run into problems. 

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Removing the fan (3 bolts and 2 electrical connections) can help a lot towards accessing the front spark plugs.

 

Also, besides unbolting the radiator at the bottom, loosening the bolt on the top (same side) will help the radiator to be pushed forward out of the way.

 

Using the factory spark plug socket and a box end wrench is also highly recommended.....not sure how you would get to the fronts without it.

 

 

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gotta be real careful as it's too easy to bend radiator fins while digging in to remove plugs.

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13 minutes ago, squirrelman said:

gotta be real careful as it's too easy to bend radiator fins while digging in to remove plugs.

Agreed, getting the fan out is a bit of a trick itself on this bike. 

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Not trying to stir the pot or anything, but I was told the Iridium plugs had a much thinner electrode so that it gets hot enough to burn off any impurities, and the actual Iridium material was used as to not "wear" out the tiny tip. The larger electrodes of standard plugs seem to get rounded off much quicker. Unless you are running insane compression ratios, or boosted intake (turbo, blower, etc...) you will likely not notice a difference, as there will not be one unless the plugs were kaput to begin with.

 

You will be fine with either plug, but since you have new, I would put them in, and check the valve cover to spark plug bore seals while you're in there. If there is a pool of oil in the bore BEFORE you take out the plug, the seal needs to be replaced.

 

+1 on the rad, I tape a piece of cardboard over it to protect the fins from damage, and my knuckles from being gouged. Don't forget to remove it afterward, or your bike will not cool properly.😉

 

Have fun wrenching!

 

 

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Since we open up and stuff, I was a victim of counterfeit Iridium plugs sold under Denso brand. Everything was made to look legit down to OEM major brand paper boxes. Bad guys went for all the trouble but adding  Iridium, skinny tip was gone in no time. Buyer be aware....

 

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HThe Online purchase before I wise up to possibility of someone counterfeiting spark plugs. Blow was also to myself not being able to tell them apart from genuine ones.

Even now after I studied the issue only one telltale is bluish hue on original electrode of new plug. Of course this hue is gone after some time in service... look at my avatar picture it shows the hue.

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I have seen youtube videos of counterfeit spark plugs from amazon and heard about other product from them also. A avoid them if at all possible.

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It's not Amazon that's selling them, they are just providing brokerage service.

Look at specific seller's ratings and reviews.

 

https://www.toyota-4runner.org/4th-gen-t4rs/273494-psa-beware-fake-iridium-spark-plugs-ex-denso-sk20r11.html

https://bobistheoilguy.com/forums/threads/more-counterfeit-ngk-iridium-ix-spark-plugs.330668/

https://www.ngkntk.com/newsroom/blog/emea/fake-products-how-to-avoid-them/

https://www.denso-am.eu/media/1372397/m28948_spark_plug_counterfeits_poster_841x594_aw_web.pdf

 

Due to their high-cost, iridium plugs is good profit-margin for scammers. I just use $2 copper plugs. Iridiums don't last 5x longer, so copper plugs work just as well, but needs to be cleaned/re-gapped or replaced more often. 

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1 hour ago, DannoXYZ said:

.....I just use $2 copper plugs. Iridiums don't last 5x longer, so copper plugs work just as well, but needs to be cleaned/re-gapped or replaced more often. 

 

Danno we shouldn’t compare price of plugs only. What you need to compare is price of labor and price of plugs. If only Iridium last twice as long as standard on a bitchin motor it is totally worthed - anything above that is just bonus 😉

 

Btw, if Amazon knowingly sells fake stuff they need to be held accountable.

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I too think amazon is culpable since you buy it through them. They need to cull the bad apples. I will gladly go to my local auto parts store to buy what I want although Denso is what I prefer and are harder to find.

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Makes me want to go pull a plug out of my Gen 5 just to take a look and see now. I installed them this past week but haven’t ridden it yet since. 

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