Spark Plugs

aardvaak

I have just bought some replacement spark plugs but they have double electrodes obviously I know how to adjust the single ones but how do I adjust the double ones?

Stigy

aardvaak wrote: »

I have just bought some replacement spark plugs but they have double electrodes obviously I know how to adjust the single ones but how do I adjust the double ones?

You don't :beer:

To be honest, even single electrode plugs tend to be pre-set adequately, although it's good practice to check nonetheless.

Double/triple electrode ones will never require checking/adjusting.

Trebor16

My understanding is that they do not require adjustment. This document from Bosch USA seems to confirm that.

http://www.euromotoelectrics.com/v/vspfiles/assets/images/boschspfaq.pdf

aardvaak

Trebor16 wrote: »

My understanding is that they do not require adjustment. This document from Bosch USA seems to confirm that.

http://www.euromotoelectrics.com/v/vspfiles/assets/images/boschspfaq.pdf

This is to fit a RAV4 the gap should be 1 -1.1mm the plugs were not that.

mikey72

You can't adjust them.

If you try, you damage the electrode, or crack the insulator, and there's the possibility it'll eventually fall off into the engine.

The gap is pre set, it'll be ok with whatever engine you put it into.
It is alo very hard to measure correctly.

Trebor16

aardvaak wrote: »

This is to fit a RAV4 the gap should be 1 -1.1mm the plugs were not that.

The relevant section is from page two of the link:-

Gaps should never by adjusted on dual or triple ground electrode spark plugs, Platinum+4 or Platinum2. These plugs have factory pre-set gaps, and should never be gapped by the installer



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atrixblue.-MFR-.

champion,denso,NGK,bosch are all pre set, do not adjust the gap especially on titainium,irriduim plugs.

moder cars are not old school where they have to be set in order to get the correct spark to have the engine running smoothly, the coil packs and cam and crank sensors adjust timing accordingly anyway for a smoothly run engine.

ive only known of one case where someone set a gap and the tip fell off into the engine, didnt make much damage but was enough to warrant a new valve so taking head off new belts tensioner waterpump and valve, headset and bolts and a few hours labour resukted ion £700 worth of damage on a focus 1.4

Stigy

atrixblue.-MFR-. wrote: »

champion,denso,NGK,bosch are all pre set, do not adjust the gap especially on titainium,irriduim plugs.

moder cars are not old school where they have to be set in order to get the correct spark to have the engine running smoothly, the coil packs and cam and crank sensors adjust timing accordingly anyway for a smoothly run engine.

ive only known of one case where someone set a gap and the tip fell off into the engine, didnt make much damage but was enough to warrant a new valve so taking head off new belts tensioner waterpump and valve, headset and bolts and a few hours labour resukted ion £700 worth of damage on a focus 1.4

I agree. I rarely adjust gaps on modern cars, only if the gap is clearly closed or close to being closed. Usually if they look about right, they are.

colino

While you can adjust multi-prong plugs, it kind of takes away from the extensive engineering that has gone into them. The plug is only going to fire off one prong anyway (the one nearest the central electrode) and they are only really there to extend sparkplug life. As the "firing" one burns away, another becomes the active one and so on. What they don't do, is give multiple sparks.