Author Topic: Spark plug gap?  (Read 491 times)

dvhttn

  • Approved Member
  • *
  • Posts: 41
  • Country: england
  • My Honda: Jazz Mk3 Ex CVT
Spark plug gap?
« on: June 23, 2022, 10:43:53 AM »
Checking the plugs in the Jazz (1.3 cvt) and can't seem to find the actual recommended gap anywhere. I know that they are almost 'fit and forget' (60 or 75K miles before being looked at etc etc) and that iridium plugs don't wear out as much but as I'm checking them I'd also like to check the gap.

Can anyone point to somewhere that actually lists this information? The nearest i could find was somewhere that quoted 1/1.1mm.

Thanks in advance.

Dave
Dave
Carpe diem

SuperCNJ

  • Approved Member
  • *
  • Posts: 243
  • Country: gb
Re: Spark plug gap?
« Reply #1 on: June 24, 2022, 01:31:00 PM »
I believe the standard plugs are NGK plugs. If you know the model number for the plug, the gap will be the last two digits of the code. So, for example IZFR6K-11S, the last two digits "11" (ignoring the S) is a gap of 1.1mm.

This is the gap NGK supply the plug with at the factory.

dvhttn

  • Topic Starter
  • Approved Member
  • *
  • Posts: 41
  • Country: england
  • My Honda: Jazz Mk3 Ex CVT
Re: Spark plug gap?
« Reply #2 on: June 25, 2022, 12:11:32 AM »
I believe the standard plugs are NGK plugs. If you know the model number for the plug, the gap will be the last two digits of the code. So, for example IZFR6K-11S, the last two digits "11" (ignoring the S) is a gap of 1.1mm.
This is the gap NGK supply the plug with at the factory.

So the NGK plugs for my car, and which I actually have fitted (well, no. 1 cylinder has an NGK plug in it .... ) are NGK DILZKAR7C11S - so a 1.1mm gap, which ties in with the info I found above. Now it also says on the NGK site that they pre-gap BUT manufacturers can specify and set their own gap and you should check the 'manufacturers manual'. Hence the question ... but as the manual says nowt I'll take it as 1.1mm and check accordingly.

Thanks.
Dave
Carpe diem

Lord Voltermore

  • Approved Member
  • *
  • Posts: 660
  • Country: gb
  • My Honda: 2021 Jazz EX
Re: Spark plug gap?
« Reply #3 on: June 25, 2022, 09:04:24 AM »
If they are NGK iridium plugs   and you know they are still within their recommended service life I would leave them alone. Assuming they are the correct specification for the car they would have been accurately gapped when new and erode very slowly compared to older type plug and ignition coil technology.     The iridium tip is very brittle and easily damaged when measuring or attempting to alter the gap. 
.
Even removing plugs just to check them visually comes with a downside.   The compression sealing washers used on many types of plug  are  meant to be 'once only' seals'  .When new they compress for a good seal.   If the plug is inserted a second time the seal is already flattened , which can affect the quality of the seal, and torque settings.

Ideally you should fit new washers if reusing , but many dont bother.  And replacement washers may not be readily available these days.     

 


   
Sorry if its too long winded. I failed my brevity exam at school. Ran out of paper.

Glosrich

  • Approved Member
  • *
  • Posts: 38
  • Country: gb
  • My Honda: 2016 Jazz S iVtec
Re: Spark plug gap?
« Reply #4 on: June 25, 2022, 11:19:48 AM »
They are pre gapped and fit and forget these days.
Just change them as per the service schedule.

93 a set of 4.

https://www.coxmotorparts.co.uk/honda-shop/genuine-honda-jazz-spark-plug-set-2016-onwards/

This is why you don't change them much!

dvhttn

  • Topic Starter
  • Approved Member
  • *
  • Posts: 41
  • Country: england
  • My Honda: Jazz Mk3 Ex CVT
Re: Spark plug gap?
« Reply #5 on: June 26, 2022, 09:28:14 AM »
They are pre gapped and fit and forget these days.
Just change them as per the service schedule.
... 

As I said in the OP, NGK say on their site that they pre-gap but to check what the manufacturer actually specifies..... Hence the original question .

But there is no way I'm going to leave a set of plugs untouched in a car for 60/70K miles. Just taken them all out and they had that 'dry metal graunching' on removal. Checked gap (near enough 1.1mm - thanks for the tip on the product code!) and replaced after the addition of some anti-seize, which also was applied to the bolts holding down the coils.

Dave
Carpe diem

BadgerMk3

  • Approved Member
  • *
  • Posts: 65
  • Country: gb
  • My Honda: Jazz Mk3
Re: Spark plug gap?
« Reply #6 on: June 26, 2022, 07:29:50 PM »
I've always believed you shouldn't use anti seize compound on spark plugs.

NGK actually state that on their website too.
https://ngksparkplugs.com/en/resources/5-things-you-should-know-about-spark-plugs#:~:text=Metal%20shell%20stretch%20changes%20the,unnecessary%20and%20can%20be%20detrimental.

dvhttn

  • Topic Starter
  • Approved Member
  • *
  • Posts: 41
  • Country: england
  • My Honda: Jazz Mk3 Ex CVT
Re: Spark plug gap?
« Reply #7 on: June 27, 2022, 10:17:48 AM »
I've always believed you shouldn't use anti seize compound on spark plugs.

NGK actually state that on their website too.
https://ngksparkplugs.com/en/resources/5-things-you-should-know-about-spark-plugs#:~:text=Metal%20shell%20stretch%20changes%20the,unnecessary%20and%20can%20be%20detrimental.

Saw that and most of their *warnings* were more to do with cack-handed installation than anything else. Along the lines of the quip about car owner manuals, "50 years ago the manual described how to check and set your valves. Today it tells you not to drink the battery acid" ....... :-)

I also note they mention having an anti-seize coating already. However that is very, very thin and from the noises/feel of removing the plugs for the first time I feel much happier with some added anti-seize of my own.
Dave
Carpe diem

plasma

  • Approved Member
  • *
  • Posts: 115
  • Country: england
  • My Honda: 2015 1.4
Re: Spark plug gap?
« Reply #8 on: June 27, 2022, 05:01:20 PM »
I've always believed you shouldn't use anti seize compound on spark plugs.

NGK actually state that on their website too.
https://ngksparkplugs.com/en/resources/5-things-you-should-know-about-spark-plugs#:~:text=Metal%20shell%20stretch%20changes%20the,unnecessary%20and%20can%20be%20detrimental.
[/qu



+1 , Same here.

Plasma.

Saw that and most of their *warnings* were more to do with cack-handed installation than anything else. Along the lines of the quip about car owner manuals, "50 years ago the manual described how to check and set your valves. Today it tells you not to drink the battery acid" ....... :-)

I also note they mention having an anti-seize coating already. However that is very, very thin and from the noises/feel of removing the plugs for the first time I feel much happier with some added anti-seize of my own.

Tags:
 

anything
Back to top