Converting inch to MM for plug gap..

[Hollow]

My plug needs a gap of .035 inches. Problem is I only have a metric gapper. I used a converter to change .035 to .889 MM. Does this sound logical and should I just gap it at .90 mm?

Thanks

[Andy-Gadget]

Yep, all you need for any conversion of inch to metric, or the other way round, is 25.4.
That is there are 25.4 mm in an inch, so 0.035" X 25.4 = 0.889 mm as you have figured.
To go the other way, just divide mm by 25.4 and the answer is in inches.

Now to the substance of your question, 0.021 mm (about a thousanth of an inch, BTW) is going to make very little difference to the spark plug.
If the gap is smaller, less energy is required from the coil to jump the gap, but will interact with less air / fuel mix.
If the gap is larger, much larger, the coil will ultimately not be able to jump the gap, and the bike won't fire at all.
And with the magnetic field flux density in the coil being a product of the dwell time, the faster the engine speed, the weaker the spark generated in the secondary winding of the coil, when the field collapses, the smaller the (large) gap that will defeat the ability of the spark to jump.
So too large a gap (much wider than 0.9 mm) will cause the bike to miss at high revs.

[Hollow]

Thanks a bunch!

[TexanInSeattle]

try this also

[the kaz]

I use this to convert since I is stupid but can type into the boxes

http://www.worldwidemetric.com/metcal.htm