ST51 NVA

[Phil Coopy]

When replacing the NVA in a FOX35 with a ST51 NVA should I turn the spraybar down to the diameter of the FOX35 spray bar or will it work as it comes out of the package.  The ST51 spraybar installed looks as though it reduces the venturi area quit a bit.

Phil

[RandySmith]

Hi Phil

If you want the same  power , break, and have the motor act  the same  you will need to turn down the ST spray bar


Randy

[Phil Coopy]

Thanks Randy! Thought there might be some secret trick burried there.

[RandySmith]

well one  trick is  to  use  a  PA stainless  FOX 35  NVA. 
another is you can just  file  the  sides of the  ST  flat  instead of turning it down,  when you turn down the  Brass  st  to  127 thou   it normally breaks  when you tighten it

Regards
Randy

[Phil Spillman]

Hi, Here's another idea! If you just use the ST NVA as supplied you can then determine if you need to do anything else! I have used a non adjusted ST NVA in Foxes without noting any difference nor detriment! So my thought is to try the thing and then make up your mind! Phil Spillman

[peabody]

I'm wondering why the Fox isn't used?

[Jim Thomerson]

Back in the 70's-80's, I could not get consistant runs with the flat-end Fox NVA.  I installed a ST NVA and intended to hog out the venturi, but never got around to it.   I was, on several occasions, accused of running an ST 46, so I would suggest try it stock, and then modify if you think it needs it.  If you do, suggest you  file the sides of the spraybar or hog the venturi.