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General Category => Maintenance => Topic started by: fj11.5 on October 01, 2012, 09:40:17 AM

Title: diaphram needle spring
Post by: fj11.5 on October 01, 2012, 09:40:17 AM
Never seen this question posted before, , but how important are  the spring rates for the needles,  as my  four year old was helping me by taking some old fj carbs apart,  and inside happend to be 4 perfect diaphams , ,, so  im going to set them  up with factory pro needles ready to drop in  just cos i can, but one spring went awhol,  as i took them apart a  few years ago,, , so can i use a spring thats almost the same rate         
, as im guessing the spring just keeps   the neeedle down in the tube,but also has some give so the needle

Dousnt bend due to  the eclipse  :scratch_one-s_head: :biggrin:
Title: Re: diaphram needle spring
Post by: hein on October 02, 2012, 07:30:09 PM
  Yes, the spring holds the needle in the vacuum piston but it also offers additional tuning opportunities. A higher spring rate would slow down throttle response and a lower spring rate would speed up throttle response. So from my perspective I would prefer that all four springs are the same.

Hein.
Title: Re: diaphram needle spring
Post by: SlowOldGuy on October 02, 2012, 08:53:39 PM
If you're talking about the spring that holds the NEEDLE down and not the one that works the Diaphragm/Slide assembly, then you don't need to worry.  Just use something that will hold the needle in place and allow you to tighten the hold-down plate.

DavidR.
Title: Re: diaphram needle spring
Post by: fj11.5 on October 02, 2012, 09:14:04 PM
thanks. mate, , yes just the one that holds the needle down, ill jam the one in I shortened up, closest I could get ,, be nice to compare needles as these are dynojet ones , didn't follow the instructions in slide drilling though, just seems to be an extra issue waiting to happen , and can't be undrilled easily  :good2:
Title: Re: diaphram needle spring
Post by: SlowOldGuy on October 02, 2012, 09:29:18 PM
Okay, I know I should remember your name, but I can't.  And I really hate conversing with a lame ID.  For some reason I just can't associate a face with an ID.

Help me out here and tell me, at least, your first name. 
I want to say Doug?

DavidR.
Title: Re: diaphram needle spring
Post by: fj11.5 on October 02, 2012, 09:45:00 PM
woops , sorry mate, rod/ Rodney or anything that gets my attention  :good2:,,