14 replies to this topic

[racingbob]

I read somewhere guy sets plugs at 50 thou

 

with electronic ignition

 

I got lucas electronic and run 35

 

any comments

[cal844]

I run them as they come out the box!

[old original]

35 thou on a 65 dizzy here

[richmondclassicsnorthwales]

I would run them at 25 really, keeps a tighter spark

[Anthony30]

No need to alter the plug gaps on multi-electrode or platinum tipped spark plugs.

[hellom8]

Don't change them out of the box.

[sonikk4]

So for all those members who do not change them out of the box why?? The one thing you need to do is check them as they may not be set to the correct gap.

[Anthony30]

So for all those members who do not change them out of the box why?? The one thing you need to do is check them as they may not be set to the correct gap.

I check my spark plug gaps just to check, but platinum tipped and multi-electrode plugs should not need setting.

[spiguy]

I used to check them diligently every time with feelers, but never found one that was 'wrong'. Seems to me that the old fingernail test is close so I just do that in case something is wildly off.

[sonikk4]

It always pays to never take something for granted. For a couple of minutes checking you will know then on single electrode plugs the gaps are good.

[Anthony30]

Has anyone else tried the Bosch multi-electrode spark plugs? They cost a fortune, compared to NGK, and made my car run   compared to NGK platinum tipped plugs, and the NGK plugs last longer. I bought them out of curiosity really, thinking they might make the car run slightly better. I was obviously wrong.

[hellom8]

I give them a check before putting them in, incase they have move in transit.

[dklawson]

+1 to Sonikk4's comments.

 

Until relatively recently pre-gapped plugs were not common.  You checked and set new plugs to be correct for your application.  The same plugs (typically Champion N9Y through the 1960s and '70s) were used in MANY British cars.  You could not assume that Champion was going to pre-gap them for your particular application.

 

Yes, modern cars often have pre-gapped plugs and in the case of NGK (and/or Denso) I believe a couple of digits at the end of the part number reflect the gap in millimeters.  So if you are going to buy pre-gapped plugs, make sure you buy the ones with the correct pre-gap or... check and set them as you won't otherwise know if they are set correctly for your engine.

Edited by dklawson, 21 January 2015 - 01:04 PM.

[newenglandmini]

My 1973 Mini 1000 Leyland owners manual and my 1976 Rover shop manual both stipulate a spark plug gap of .025" for my 998 cc engine.  My Haynes Mini manual (which purports to cover all Mini variants from 1969 to 2001) stipulates a gap of 0.8mm (.032").  Any idea why the Haynes manual has a different specification?

[Earwax]

newengland mini, no idea really, but typically 25 thous was for points system, whilst electronic dizzy versions(aftermarket) can utilise a larger gap (again typically 32 thous., but i have seen 35 thous... the coils in these systems MAY be different (resistance) so need to check this as well