Factory Pro designs and produces the best performing">
Factory Pro designs and produces the best performing, highest power, easiest to tune carb kits around and makes the EC997 dynos that can see the difference in engine smoothness.........

So.... why wouldn't we rely on the zootiest spark plugs around? Plugs that require up to 5000 LESS volts to fire  than even platinum electrode plugs!

Our EC997 dynos are the only dynos that you can cost effectively buy that will actually display "engine smoothness" - We call it the FLUX factor - It's how smooth the engine is - as in 2nd gear, low rpm cruise through town -
The Denso Iridiums, time after time, will improve fuel burn consistency, delivering less handlebar buzz (when tuned properly) -

Denso Iridium Spark Plugs
Factory Pro is a stocking MC distributor - Call for detailed information.

NOW AVAILABLE:  Denso Iridium spark plugs!  Most motorcycle applications IN STOCK!

Find My Plug! Motorcycle Denso MC Application Guide
Find My Plug!
Karts / Snowmobile / Personal Watercraft
Denso K-S-PW Application Guide
Spark Plug Specifications
(when you know what length. diameter, style you want!)
Know your spark plug numbers now and want to upgrade to Iridium power?  Cross Reference Guide
De-mystify Denso Iridium spark plugs part numbers
(the most descriptive source around!)
Part Numbers decoded!
How to install spark plugs! Official "How to" guide
Denso (ND, Nippon Denso) is the largest OEM supplier for autos and motorcycles of electrical components in the world. Sometimes, people forget that Denso makes pretty darn good spark plugs, too! Wide heat range properties discourage plug fouling at low speed AND overheating at high speed.

We have been using Denso spark plugs in our AMA Supersport bikes since Denso was Nippon Denso and ND. We have found that some standard, <$10, off the shelf, Denso spark plugs work as well as $75 special spark plugs - on a professional roadrace level!

For more detail on decoding Denso plugs, click here.

True Rear Wheel HorsepowerŽ Factory EC997aŽ Eddy Current Dynamometer