Spark plug gap.

85 ZN-700A2 Bike is running well and the plugs were new, so I was told, when purchased in March. I check the plugs periodically for color, wet/dry, etc, but for some reason I never checked the plug gap until today. The owners manual state the proper gap range is .028 - .032. My plugs were gapped to .034.

My question is will that .002 difference in over gap make any real difference at all? I have not ridden it since I reset them to .030. Just curious. I may just pick up some new plugs just for the hell of it too.

If the plug color looks good I wouldnt give it a secound thought. I run mine A little wider open with excell coils. Regards Pete

I believe a forum member "Otakar" runs on 2.2 ohm Grey Dyna coils at least 0.045", but ask him what he's done to the engine/ignition system.

will an over gapped plug cause the plus to foul? i was told the gap should be .40 on my bike. i just looked in the manual and its saying .28-.32 and will it make it run rough?

dmrcflyr2 wrote: 85 ZN-700A2 Bike is running well and the plugs were new, so I was told, when purchased in March. I check the plugs periodically for color, wet/dry, etc, but for some reason I never checked the plug gap until today. The owners manual state the proper gap range is .028 - .032. My plugs were gapped to .034.

My question is will that .002 difference in over gap make any real difference at all?

no. It makes a microscopic increase in the voltage level at which the spark jumps the air gap but the spark energy is unchanged.

Going WAY up in gap well above the factory spec can destroy stock coils over time since the larger gap forces the secondary winding in the coil up to a much higher voltage each time it fires. Some hi perf coils are designed for it, stock coils maybe not.

NGK Info

I am gonna throw my 2 cents in I agree with the if the plugs look good dont mess with them. I am gonna also add I am not a tech but my family who have maters certificates and fabrication endorsements ran .04 off national records, brothers dad etc.. and while gapping plugs i was always told the tab should be level and square with the electrode and I think after propper gapping you will find that more times than not