Spark plug gap questions.

[tbourner]

OK so I'm trying to do my plugs, but exactly what gap should I be using and how precise does it need to be?

 

 

Alex's spark plug FAQ says:

TT @ upto 1bar

NGK - BCPR7ES (3330) - gap 0.9mm

NGK - BKR7E (6097) - gap 0.9mm

NGK - Iridium - BKR6EIX or BKR7EIX - leave gap alone

Denso Platinum - PK20R11 - gap 0.8mm

Denso Iridium - IK22 - leave gap alone

 

TT/hybrids @ upto 1.3bar

NGK - BCPR7ES (3330) - gap 0.7mm

NGK - BKR7E (6097) - gap 0.7mm

NGK - BKR8E - gap to 0.7mm

NGK - BCPR8ES (3330) - gap 0.7mm

NGK Iridium - BKR7EIX - leave gap alone

NGK Iridium - BKR8EIX - leave gap alone

Denso Platinum - PK20R8 - gap 0.7mm

Denso Iridium - IK22 - leave gap alone

Denso Iridium - IK24 - leave gap alone

 

But that's a big change, 0.7mm - 0.9mm!!! And I'm running 1.15 Bar so should I do what I did last time and do it to 32 thou (0.8mm)?

 

How do I know what my gap should be without keep taking the plugs out and making it ever smaller until it misfires!!! I'm still new so this still takes an hour each time!!!

 

 

 

Also, how precise does it need to be? Can one plug be 0.8mm and the next be 0.75mm?

 

And how tight should the feeler guage be in the gap? When I was misfiring I couldn't get the 0.8mm feeler in!!! Had to wiggle it about a bit. Should it go in smooth and easy or should there be some resistance?

 

 

 

 

And this is the easiest DIY job - I can make a meal out of anything!!

[b_have]

Gap smaller if it misfires. I need to gap mine to .028" (0.7mm) any bigger and it misses >1.4bar.

[tbourner]

Well I had too small a gap before, hence I had problems all over Christmas with poor idle. I regapped the 2 small gaps and it was ok.

Now I'm having a similar problem and I'm just going to change the plugs completely but unsure what gap to choose.