Home Shop Ignition Spark Plugs Spark Plugs #10-12: Buell und V-Rod VRSC
Click here to recommend this page to others

Spark Plugs #10-12: Buell und V-Rod VRSC

... more

Spark Plug Heat Ranges

Harley spark plug heat ranges are marked by numbers, from 2 to 12. No. 2 is the hottest plug, no. 6 would then be a relatively cool plug. The coolest plug used by Harley-Davidson is marked 10R12A. Double numbers characterize multi-range plugs.

With older motors, it was not uncommon, that you achieved an optimum with plugs of two different heat ranges. Unlike the well known prejudice implied, you had to choose cooler plugs for the front and hotter plugs for the rear cylinder. On later Harley engine designs, heat distribution is balanced to such an extent that you should not have to rely on those tricks anymore.

Stroker owners should refer to OEM instructions for their specific type of motor, unless the manufacturer recommends entirely different plugs.
Spark plug; fits Buell and V-Rod VRSC; thread: M12 x 1.25; thread length: 3/4 ”; wrench size: 5/8 ”; OEM labelling: 10R12A; replaces OEM 27671-01K, and 32335-04
W&W# Picture net price* Available from warehouse Germany?
12-089 Spark Plugs #10-12: Buell und V-Rod VRSC »OEM«; manuf. labelling: 10R12A; USA $7.90 each
in stock
12-099 Spark Plugs #10-12: Buell und V-Rod VRSC by Champion; manuf. labelling: RA6HC $4.71 each
in stock
* United States of America: Tax free shipping. Please check your local import fees.

See also:

  • C. Walter Spark Plug Wire Brushes

    C. Walter Spark Plug Wire Brushes Don´t get caught without it! This little brush should be part of any tool roll or tool box. Cleans sooty plugs in seconds so you are back on the road in no ...

  • Loctite 8065 Thread Lubricant

    Loctite 8065 Thread Lubricant Copper paste stick to lubricate threaded connections. Compared with liquid counterparts these sticks with semi-solid consistency offer some advantages: optimum ...

  • GearWrench Spark Plug Sockets 3/8”

    GearWrench Spark Plug Sockets 3/8” Special, deep sockets for spark plugs. They feature an external hex which allows the use of wrenches when space is limited. Rubber inserts hold the plug when ...

Have any questions?

  • Our sales team will be glad to help out:
    Mondays - Fridays 08:00-18:00 CET, Saturdays 09:00-13:00 CET
    Phone: +49 / 931 250 61 16
    eMail: sales@wwag.com