NOTICE:  These are tech pages explaining how I did these mods to my bike.  In almost every case -
I DO NOT SELL THE PARTS DESCRIBED.  I do tell you where I got them.  EXCEPTION - I do sell my custom exhaust mods. 

Tech Tips
Valk Products
My Valkyrie

Upgrading Valkyrie Headlight Circuit for High Power Bulbs



      This mod increases the capacity of the headlight circuit to handle high power bulbs without risk of damage to the existing headlight circuit. Power is supplied to the filiments via seperate circuits that are activated by two relays, which in turn are controlled by the original headlight power circuits. Consequently, the power through the original circuits are significantly less than stock, which should increase the lifetime of those circuits, especially the high-low beam switch. I originally recommended using a dual relay which is what I used in these pics, but you can save about $15 by using two general purpose relays from Pep Boys (or any other auto parts outlet).


      About $23 not including the high output bulb


      3-5 hours


    • 1 8ft length of multistrand 14 gauge wire
    • 1 8" section of loom
    • 1 20amp inline fuse with 14ga wire
    • 1 partial roll electrical tape
    • 2 sizes for 18GA and 14GA wire, heat shrink tubing
    • 2 general purpose 3-wire relays, at Pep Boys, Motormite PN 84607
    • 2 sizes wire ties
    • 1 self tapping sheet metal screw
    • 1 medium washer
    • 1 stick hot melt glue
    • 3 14 ga female quick disconnect spade connectors
    • 2 18-22ga female quick disconnect spade connectors
    • 1 high-watt headlight bulb, one place it's available is Competition Accessories, to order their catalog/ order stuff. High watt bulbs available from C.A. are 100/55, 100/80, 100/90, 130/90. FYI stock wattage is 60/55


    • Wire cutters
    • Wire stripper
    • needlenose pliers
    • soldering iron
    • elect solder
    • flux
    • glue gun
    • phillips screwdriver
    • 10mm wrench


      Remove the seat, gas tank and the headlight. Disconnect positive lead on battery. Solder 14GA wire to one end of the inline fuse wire after positioning shrink tube on the wire. Shrink the tube over the splice. Drill appropriate hole in fitting on end of main battery cable. Strip 1/2" of end of other wire on inline fuse, form into loop to fit screw, tin it with solder and affix the wire to the cable with the screw. Run the 14GA wire along the frame taking care it is not subject to pinching from anything (like the tank) and secure it with wire ties.

      Pass the wire through the hole in the back of the headlight shell, and slip the loom sleeve over it. Pass the loom half way through the hole and secure it to the other wire looms with small wire ties. Cut the wire off, leaving about ten inches beyond the end of the loom.

      Cut the wires close to the headlight plug. Carefully remove the contacts from the plug (depress the spring catch on the brass). Open the crimp using a sharp tool, remove the wire.

      Referring to the wiring diagram and the picture, assemble the circuit in the diagram using the connectors, heat shrink tubing, electrical tape, solder, and three pieces of the 14GA wire each about ten inches long. Carefully reuse the three plug contacts by recrimping them. (I also soldered them, and have not had a problem with the solder melting.) Use one of the forward screws in the bottom of the headlight shell to ground the two wires, using the washer.

      Bend the mounting flange of the relay, and open the hole slightly to mount the relay using the rear bolt in the bottom of the shell. Also NOTE - the headlight shell gets a lot of water in it - so use a hot glue gun and seal the back of the relay. Use heat shrink tubing and electrical tape to completely insulate the quick disconnects.Reconnect the battery and do a smoke test.

      I have about 25,000 miles on this mod, and am pleased it hasn't melted the headlight lens.  You may want to re-aim the light a little higher to use all those watts - turn in the right adjuster to move the aim up - the 130 bulb will light up the road for a measured 1/2 mile.

All technical mods described here are merely reports of what I've done.  You may attempt to replicate them at your own discretion and risk if you choose.  Horseapple Ranch, LLC and Mark Tobias will in no way be responsible for the results of your attempting to perform these mods on any motorcycle, regardless of the outcome.

All content on copyright 1999-2006 Mark Tobias except "Riders Say", "Dyno Day", Vallejo and Shop Manual and Alternator Review pages, and SWF and MP-3 files and their graphic icons, and any content specifically attributed to another author.  
All rights reserved.