Is putting a QF-2 spring in my CFX a good idea?

[fisherdude]

I have started seeing what I believe is spring tar working its way into the pressure chamber on my CFX and accuracy is waningand it smokes.  So I am taking it down again and cleaning it up.  I think one of the problems is that I had to use quite a bit of JHT to quiet the twang from the spring.  The tolerences for the factory spring/top hat/guide are pretty loose which I think contributes to the twang.  Just for grins, I took out a QF-2 spring and I think it would fit if I turned down the top had and guide a little.  The spring has a little smaller outer diameter.  
Any way, the original spring isn't that bad, I just don't like twang.  So if anyone has any thoughts on how to keep tar out of the pressure chamber the advice would be appreciated ( btw, I put in a new seal and nothing changed).  I think I may have just had to use too much JHT.  I used very little molly.  I guess I could have a whole new tophat/guide made with a new spring/seal, it just seems to me that since I already have a spring and I think turning down the existing top hat and guide is doable with the tools I have to work with.

Your thoughts?

[SDale]

If tar is getting into the compression chamber, then you used too much.


AS far as springs go, I read that someone here used a QF2 spring in a .177 Crosman Quest and got the same chrony numbers as the factory spring. I also tried it with a .22 Quest with the same restults for the first 2-300 shots. Then velocity dropped 70+ FPS.

[Fritz]

I would put a JM kit in your CFX. Make sure you get his secret tar.

[TexasShooter72]

It's a little pricey but send it to David Slade for a Theoben gas ram!  He's making his own proprietary seals too!  The breech seal is the biggest pain in the rear with the CFX and he's got a solution to it!  He's rammed 2 of my rifles and I cannot say enough good things about him.