Knife won't open because Assisted Opening Spring is too strong

[bystander23]

Hi,
I need some how-to help for a Tac-Force TF-469 AO Knife I just acquired (<$7.00). I know this brand is

either loved or hated, but I'm staying out of that argument. While I have a problem with this knife, it

would cost more than it's worth to try to return it, and I really don't want to throw it away. I do like to

tinker and fix things (if I can).
Here's my problem. The spring tension is still way too high even after extreme adjustment of the pivot

screw (I'm talking "about to come out"). The flipper is the only way it opens okay. I cannot open it via

the thumb stud. Pulling the blade out manually is very difficult since the black coating on the blade is a

bit slippery and there's not much blade to grab either. I've also noticed a grinding sound when pulling out

the blade manually.
I removed the bolsters covering the spring, and noticed a few things. The spring is flat and M-shaped with a

long curved section going to the hole in the blade that circles around the pivot. The frame has a

rectangular hollowed-out section for the spring to sit in, and the end of that section provides the backstop

for the M-shaped "coil". The pivot "bearing" looks like a mis-shapened gear. When the blade is in the

closed position, it almost seems like the spring tip is "catching" either on a tooth of the 'gear' or on the

frame in that arc around the pivot, I'm just not sure. (I have to hold the spring in place with my fingers

to check this.)
Without the spring, the knife opens easily either manually or with the stud, but then the flipper requires a

wrist-flip to engage the liner lock. I don't feel safe closing the blade without any spring, but it requires

quite an effort to close it with the spring in place, and that's not good either.
All the above is to ask this question - Is there a way to reduce the tension of this spring? It appears

that the spring needs to be "shortened", but I don't know if squeezing the coils is better than clipping off

the right-angle bend at the other end and trying to make a new bend.
I appreciate any help you can give me! Thank you!

 

[bystander23]

I wish someone in the forum could have offered me some advice, since I originally thought that more people would have come upon knives that were sold as quick-opening models that were anything but! Since I hadn't had any replies since my original post, I decided to try and tackle the problem myself.
I squeezed the flat M-shaped spring's legs to shorten the spring's overall length, added some graphite powder in the hollowed-out channel and re-assembled the knife. The flipper still works, but now I can open the knife with the thumb-stud and two hands. Prior to my "fix", I was having major difficulty opening the knife at all unless I used the flipper.
I am hoping that wear and tear and time will eventually work in my favor so this knife can be opened as quickly with the stud as it opens with the flipper.
Take care, people.

 

[bpeezer]

An assisted open knife should NOT be that difficult to open. If you could post a picture of the inner workings it might help. Also, there should be no concerns about having the knife as a strictly manual folder if the problem persists. You may have luck going to the local hardware store and seeing if you can pick up a similar spring with lower tension, or some wire that you could bend into a spring. In the future, stay away from $7 knives