Optimum sparkplug gap question

NGK I believe recommends 0.028" to 0.031" gap for their sparkplugs in the Kawasaki engines.

I've read that some riders will open the gap to 0.040" with no problems(I'm assuming the stock coils are replaced with Dyna green or grey coils).

What are you running,and any problems?
Also brand of sparkplug,NGK,Denso,Accel?

kzrider.com/index.php?option=com_kunena&...ew&catid=4&id=351334

Enjoy.

Increasing the gap forces the coil to go to a higher open circuit voltage before it sparks which some have claimed increases spark "energy". From what I remember about flyback converters and transformers, thats bogus. The flyback stores energy in the form of:

1/2 L (I) squared

in the core during the time the points are closed, and then releases the enrgy when the points break. As the voltage builds up on the secondary, a wider gap keeps it from firing until it gets to a higher voltage, but it does not increase the stored energy at all.

I run a CDI on mine that puts out a higher open circuit voltage, but I have never seen convincing proof that a higher spark voltage (or wider plug gap) has any beneficial effect at all.

Would be interested if there is any independent lab data showing power gain or mileage increase. Mostly, I just read a lot of baloney about "long fat sparks" and what not. No actual data.

I understand the Dyna systems that allow precise advance mapping could give performance improvements but that is unrelated to spark voltage or energy.

I've experienced less smoke on a 2-stroke by opening the gap some, but no performance gain.

The gap is set by the manufacturer with the electronics and compression in mind. basically just enough spark to ignite things effectively at low and high rpm, and small gap to keep coils and stuff lasting as long as possible.

Set it wherever you want and see what happens.
A gap too large can cause issues at high rpm.
A gap too small can cause stumbly idle.

GL