Surefire 6Z KX4D upgrade problem

[Bobertrd]

I just got the surefire KX4D upgrade for my surefire 6Z, but when I put it on, it does not work properly. It appears the spring that connects to the bulb and makes contact with the batteries is shorter than the original, which explains why the light flashes on and off when it is shaken gently. Also, the tail cap does not work properly with the new KX4D.

Has anyone else had this problem, and if so, how was the problem solved? Obviously I cannot use a light that is giving away my position, and does not come on when I push the tail cap.

 

[kelmo]

Welcome to CPF!

I bet its the tailcap. The battery should travel freely to the spring on the KX4. If this is an old tailcap that the spring and button assembly comes out when disengaged from the body then try a newer lock out tailcap. I have an old 6P with the before mentioned tailcap and it won't work with aftermarket LED modules like the Malkoff series.

I really like the KX4D. I have one on a 6P tube myself.

kelmo

 

[HotWire]

I bought a KX4D and it works on several Surefire tubes. No problems. I was never impressed with throw or brightness, though. You could stretch the spring on the tailcap a little. Or you could call Surefire and explain the problem. They will probably send you a new tailcap.