7 replies to this topic

[BaronVonchesto]

Hi guys,

 

I have a HS4 carb (AUD type). As part of my carb rebuild i figured might as well change the needle too, even though the needle seems fine.

 

Unfortunately the carb needle seems to be stuck! Its the spring loaded swinging type, and I removed the locking screw in the piston, but cant pull out the needle. I know that it should drop away easily, but pulling by hand I just cant seem to get it out.

 

Anyone have a solution for this?

[hhhh]

If it's corroded looking at all, let some penetrating oil soak in for a bit, then carefully put it in a pot of boiling water for a minute, take it out, let it cool for a moment and pinch it hard with your finger and thumb at the base and work it out, or it may just fall out from the heat.

[carbon]

As above. If that does not work then a very gentle tap with hammer and small drift onto the steel inner collar may help to break any gunk. But be carfeul how you clamp the piston, as the outer surface is a very close tolerance inside the dashpot.

[Retroman]

It will be interesting to see what works best...if the above don't work and as you are not using the old needle you can use a pair of pliers tight on the needle and sort of lever it out, taking care not to damage the bottom of the piston.

[BaronVonchesto]

kinda old now, but I figured I'd give an update for anyone else that might benefit from this experience.

 

Wrapped the piston in a hand towel and put it into a bench clamp gently. Sprayed liberal amounts of penetrating fluid and left it to soak in over 24 hours. Needle was still stuck, so i sprayed more penetrating fluid, waited 10 minutes, then took a small screwdriver and used a mallet to gently tap the ring surrounding the needle.

 

A few taps and the ring went in, then pulling on the needle, the ring came out a little. just enough to grip it with needle nose pliers and pull it out.

 

So i got the needle out. yay!

[yeti21586]

Well done buddy

[Vipernoir]

I've always done it the other way round - clamp the needle in the vice as there's more piston to pull on.

 

The needle at this point is sacrificial, so winding the vice up really tight isn't an issue and if it is still really stubborn you can use a pair of lever bars under the base of the piston.

[Retroman]

Good at least its out without any damage

 

Now it is out get the little holder in the vice and pinch it very gently to close the  'gap'  a fraction

 

It should go back in the hole easily.

 

When refitting the needle don't over-tighten the screw as you know what happens...